unexpected keyword argument 'value_serializer'

[temuller]

I recently updated jupyter book and tried building a book but got the following error:

Running Sphinx v3.5.4
[etoc] Changing master_doc to 'Intro'
loading pickled environment... failed
failed: build environment version not current
myst v0.13.6: MdParserConfig(renderer='sphinx', commonmark_only=False, dmath_allow_labels=True, dmath_allow_space=True, dmath_allow_digits=True, update_mathjax=True, enable_extensions=['colon_fence', 'dollarmath', 'linkify', 'substitution'], disable_syntax=[], url_schemes=['mailto', 'http', 'https'], heading_anchors=None, html_meta=[], footnote_transition=True, substitutions=[], sub_delimiters=['{', '}'])

Exception occurred:
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/sphinx_external_toc/api.py", line 152, in <dictcomp>
    for k in sorted(self._docs)
TypeError: asdict() got an unexpected keyword argument 'value_serializer'
The full traceback has been saved in /tmp/sphinx-err-q__1wxs1.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
Traceback (most recent call last):
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/jupyter_book/sphinx.py", line 150, in build_sphinx
    site_map_str = yaml.dump(site_map.as_json())
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/sphinx_external_toc/api.py", line 152, in as_json
    for k in sorted(self._docs)
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/sphinx_external_toc/api.py", line 152, in <dictcomp>
    for k in sorted(self._docs)
TypeError: asdict() got an unexpected keyword argument 'value_serializer'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/tomas/anaconda3/envs/pisco/bin/jupyter-book", line 8, in <module>
    sys.exit(main())
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/jupyter_book/cli/main.py", line 317, in build
    result, builder, OUTPUT_PATH, build_type, PAGE_NAME, click.echo
  File "/home/tomas/anaconda3/envs/pisco/lib/python3.6/site-packages/jupyter_book/cli/main.py", line 516, in builder_specific_actions
    raise RuntimeError(_message_box(msg, color="red", doprint=False)) from result
RuntimeError: 
===============================================================================

There was an error in building your book. Look above for the cause.

===============================================================================

Any idea what is happening here?

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[chrisjsewell]

Heya what version of attrs do you have? The version requirements are specified here: https://github.com/executablebooks/sphinx-external-toc/blob/5f0cbdc568580875d5909a3de967c1963b7f858e/setup.cfg#L32

[temuller]

Hi! I installed the latest version of attrs and it worked! Thanks!