Possible ePub Conversion Problem in 0.6.49 ???

[GJN]

Ran into the following problem, trying to convert a public domain e-book (Sayers, Gaudy Night) from ePub format to ePub format. I wanted my own cover art to correct the supplied title.

The book was obtained from https://www.mobileread.com/forums/showthread.php?t=81194

I got the following error, which I hadn't encountered before. Your help in resolving this problem would be much appreciated.

ERROR: Conversion Error: <b>Failed</b>: Convert book 1 of 1 (Gaudy Night)

Convert book 1 of 1 (Gaudy Night)
Resolved conversion options
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'change_justification': u'original',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., 'chapter|book|section|part\\s+', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': '/var/folders/Uo/UoQM52YaFyCXcZn8gnSzJE+++TI/-Tmp-/calibre_0.6.49_ebcrHt.jpeg',
'debug_pipeline': None,
'disable_font_rescaling': False,
'dont_split_on_page_breaks': False,
'extra_css': None,
'extract_to': None,
'flow_size': 260,
'font_size_mapping': None,
'footer_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'header_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x6cb3710>,
'insert_blank_line': False,
'insert_metadata': False,
'isbn': None,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'max_toc_links': 50,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_inline_navbars': False,
'output_profile': <calibre.customize.profiles.KindleOutput object at 0x6cb39f0>,
'page_breaks_before': u"//*[name()='h1' or name()='h2']",
'prefer_metadata_cover': False,
'preprocess_html': False,
'pretty_print': True,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': '/var/folders/Uo/UoQM52YaFyCXcZn8gnSzJE+++TI/-Tmp-/calibre_0.6.49_yOhyjG.opf',
'remove_first_image': False,
'remove_footer': False,
'remove_header': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'series': None,
'series_index': None,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: EPUB Input running
on /GJN Files/Kindle Books/Sayers_ Dorothy L_/Gaudy Night (2277)/Gaudy Night - Sayers_ Dorothy L_.epub
Found HTML cover OEBPS/text/content001.xhtml
Parsing all content...
Parsing OEBPS/text/content023.xhtml ...
Parsing OEBPS/text/content025.xhtml ...
Parsing OEBPS/text/content027.xhtml ...
Parsing OEBPS/text/content029.xhtml ...
Parsing OEBPS/text/content006.xhtml ...
Parsing OEBPS/text/content002.xhtml ...
Parsing OEBPS/text/content004.xhtml ...
Parsing OEBPS/text/content005.xhtml ...
Parsing OEBPS/text/content008.xhtml ...
Parsing OEBPS/text/content010.xhtml ...
Parsing OEBPS/text/content012.xhtml ...
Parsing OEBPS/text/content014.xhtml ...
Parsing OEBPS/text/content018.xhtml ...
Parsing OEBPS/text/content020.xhtml ...
Parsing OEBPS/text/content022.xhtml ...
Parsing OEBPS/text/content024.xhtml ...
Parsing OEBPS/text/content026.xhtml ...
Parsing OEBPS/text/content028.xhtml ...
Parsing OEBPS/styles/style001.css ...
Parsing OEBPS/text/content001.xhtml ...
Parsing OEBPS/text/content016.xhtml ...
Parsing OEBPS/text/content003.xhtml ...
Parsing OEBPS/text/content007.xhtml ...
Parsing OEBPS/text/content009.xhtml ...
Parsing OEBPS/text/content011.xhtml ...
Parsing OEBPS/text/content013.xhtml ...
Parsing OEBPS/text/content015.xhtml ...
Parsing OEBPS/text/content017.xhtml ...
Parsing OEBPS/text/content019.xhtml ...
Parsing OEBPS/text/content021.xhtml ...
Reading TOC from NCX...
Merging user specified metadata...
Detecting structure...
Detected chapter: Chapter 1
Detected chapter: Chapter 2
Detected chapter: Chapter 3
Detected chapter: Chapter 4
Detected chapter: Chapter 5
Detected chapter: Chapter 6
Detected chapter: Chapter 7
Detected chapter: Chapter 8
Detected chapter: Chapter 9
Detected chapter: Chapter 10
Detected chapter: Chapter 11
Detected chapter: Chapter 12
Detected chapter: Chapter 13
Detected chapter: Chapter 14
Detected chapter: Chapter 15
Detected chapter: Chapter 16
Detected chapter: Chapter 17
Detected chapter: Chapter 18
Detected chapter: Chapter 19
Detected chapter: Chapter 20
Detected chapter: Chapter 21
Detected chapter: Chapter 22
Detected chapter: Chapter 23
Flattening CSS and remapping font sizes...
Source base font size is 12.00000pt
Cleaning up manifest...
Trimming unused files from manifest...
Parsing stylesheet.css ...
Trimming 'OEBPS/text/content001.xhtml' from manifest
Trimming 'OEBPS/images/img0002.jpg' from manifest
Python function terminated unexpectedly: Invalid predicate
Creating EPUB Output...
Traceback (most recent call last):
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 147, in main
return run_entry_point()
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 116, in run_entry_point
return getattr(pmod, func)()
File "site-packages/calibre/utils/ipc/worker.py", line 99, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 24, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 902, in run
File "site-packages/calibre/ebooks/epub/output.py", line 140, in convert
File "site-packages/calibre/ebooks/oeb/transforms/split.py", line 56, in __call__
File "site-packages/calibre/ebooks/oeb/transforms/split.py", line 63, in split_item
File "site-packages/calibre/ebooks/oeb/transforms/split.py", line 118, in find_page_breaks
File "xpath.pxi", line 409, in lxml.etree.XPath.__init__ (src/lxml/lxml.etree.c:104197)
File "xpath.pxi", line 184, in lxml.etree._XPathEvaluatorBase._raise_parse_error (src/lxml/lxml.etree.c:102112)
lxml.etree.XPathSyntaxError: Invalid predicate

[kovidgoyal]

Looks like it is something specific to that EPUB file, apparently a malformed id. You can work around it by setting page breaks before to /

[GJN]

Thanks, Kovid.