Error exporting RTF only

[Quoth]

calibre, version 5.11.0
WARNING: Error while saving: Failed to update metadata in some books, click "Show details" for more information

Failed to update the metadata in the RTF format of: The Red Fairy Book by Andrew Lang, with error:
    Traceback (most recent call last):
      File "sre_parse.py", line 1039, in parse_template
    KeyError: '\\s'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "calibre/customize/ui.py", line 447, in set_file_type_metadata
      File "calibre/customize/builtins.py", line 559, in set_metadata
      File "calibre/ebooks/metadata/rtf.py", line 217, in set_metadata
      File "calibre/ebooks/metadata/rtf.py", line 209, in replace_or_create
      File "re.py", line 327, in _subx
      File "re.py", line 318, in _compile_repl
      File "sre_parse.py", line 1042, in parse_template
    re.error: bad escape \s at position 1 (line 1, column 2)

Maybe it doesn't matter? I'm not actually interested in metadata when I export RTF, which is usually to get something into the wordprocessor.

[kovidgoyal]

Yes its harmless, just means metadat was not updated.

https://github.com/kovidgoyal/calibr...3269b0c836a4a9

[Quoth]

Thanks.
I suspected that.