Build fails with TypeError: unhashable type: 'list'

[Davide-sd]

Details

• Read the Docs project URL: https://readthedocs.org/projects/sympy-plot-backends/
• Build URL (if applicable): https://readthedocs.org/projects/sympy-plot-backends/builds/24204752/
• Read the Docs username (if applicable): https://readthedocs.org/profiles/Davide_sd/

Expected Result

Successfully building the documentation.

Actual Result

I'm getting this error, from which I'm unable to pinpoint what the problem is.

# python -m sphinx -T -b html -d _build/doctrees -D language=en . $READTHEDOCS_OUTPUT/html

 Running Sphinx v7.3.7

Traceback (most recent call last):
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/cmd/build.py", line 332, in build_main
    app = Sphinx(args.sourcedir, args.confdir, args.outputdir,
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/application.py", line 268, in __init__
    self._init_builder()
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/application.py", line 338, in _init_builder
    self.builder.init()
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 220, in init
    self.build_info = self.create_build_info()
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 246, in create_build_info
    return BuildInfo(self.config, self.tags, frozenset({'html'}))
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 142, in __init__
    values = {c.name: c.value for c in config.filter(config_categories)}
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 142, in <dictcomp>
    values = {c.name: c.value for c in config.filter(config_categories)}
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/config.py", line 451, in <genexpr>
    return (value for value in self if value.rebuild in rebuild)
TypeError: unhashable type: 'list'

Exception occurred:
  File "/home/docs/checkouts/readthedocs.org/user_builds/sympy-plot-backends/envs/latest/lib/python3.10/site-packages/sphinx/config.py", line 451, in <genexpr>
    return (value for value in self if value.rebuild in rebuild)
TypeError: unhashable type: 'list'
The full traceback has been saved in /tmp/sphinx-err-9pvnt8ll.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!

Note that my last successful build was about 2 weeks ago, using Sphinx v7.2.6. Since then, I haven't modified .readthedocs.yml, but I changed conf.py (on my local machine, the build runs fine with an older version of Sphinx).

The error message mentions the file /tmp/sphinx-err-9pvnt8ll.log. Is there a way to access it?

[humitos]

Hi. The latest successful build I found in your documentation was using Sphinx v7.2.6. I assume the upgrade to 7.3.7 may break something on your project. I'd suggest you to pin the version of Sphinx to 7.2.6 as a first test to verify if this is related to the Sphinx version or not.

[Davide-sd]

Hi @humitos , thanks for the suggestion. I've set sphinx==7.2.6 in requirements.txt and the build succeeded. Then, I guess it's something related to Sphinx...