Sphinx 6.0.0: Theme Error: Reason: UndefinedError("'logo' is undefined")

[juliotux]

After upgrade to sphinx==6.0.0, a ThemeError is raised. This error disapear when using another theme, so I think it's related to pydata_sphinx_theme.

looking for now-outdated files... none found
pickling environment... done
checking consistency... done
preparing documents... done
writing output... [  0%] api/astropop.astrometry.AstrometricSolution                                                                                                 
Theme error:
An error happened in rendering the page api/astropop.astrometry.AstrometricSolution.
Reason: UndefinedError("'logo' is undefined")
make: *** [Makefile:45: html] Error 2

[pgjones]

I'm also seeing this on a different project.

[sdpython]

I added a section logo in html_theme_options and it worked:

html_theme_options = {
   "logo": {
      "image_light": "logo-light.png",
      "image_dark": "logo-dark.png",
   }
}

[12rambau]

The problem is coming from here:

pydata-sphinx-theme/src/pydata_sphinx_theme/theme/pydata_sphinx_theme/components/navbar-logo.html

Line 10 in 13d4692

{% set is_logo = logo or theme_logo.get("image_light") or theme_logo.get("image_dark") %}

I need to investigate but it seems the default "logo" (provided by Sphinx itself) is not reaching the template anymore.

As a workaround and as @sdpython suggested, you can rely on the html_theme_options logo to overwrite Sphinx definition.

[mgeier]

Apparently, logo and favicon were removed in Sphinx 6, see sphinx-doc/sphinx#11062 and sphinx-doc/sphinx#11063.

[prjemian]

I'm seeing this same error when writing the first page:

| pickling environment... done
| checking consistency... done
| preparing documents... done
| writing output... [ 25%] changes                                               
| Theme error:
| An error happened in rendering the page changes.
| Reason: UndefinedError("'logo' is undefined")

[prjemian]

No text logo anywhere in the pysumreg repository, BTW.

[prjemian]

The error was encountered in a local CI build of the publishing workflow using act. The local CI installs Downloading sphinx-6.0.0-py3-none-any.whl (3.0 MB). The error is reported on the first file to be output.

Adding an installation restriction on the Sphinx version allows the build to complete:

      - name: Install Sphinx build requirements
        run: |
          pip install setuptools-scm "sphinx<6" pydata-sphinx-theme
          echo "--------------- diagnostic pip list ---------------"
          pip list

[12rambau]

As long as 0.13 is not released, the fix we provide won't be available. Please pin the version of Sphinx to sphinx<6 in your documentation environment.

[leycec]

Intense blocker here. Pinning sphinx<6 is non-ideal; inevitably, I forget I've even done that and then something explodes five years from now. Panic from my future self can already be heard.

Would publishing a rapid 0.12.1 patch release just addressing this specific issue be feasible instead, perhaps? Probably not – but a criminally forgetful dev-bro can beg on GitHub. 🥺

[12rambau]

solved in #1132 and included in 0.13.0rc1. 0.13 will be released soon.