Many themes fail with 'style' is undefined since Sphinx 7.0.0's release

[vwheeler63]

Hello. As I write this it is about 21:00 GMT (15:00 Mountain Daylight Time). About 24-28 hours ago, all of the themes at https://sphinx-themes.org were displaying correctly. However, today I went to look at the list more thoroughly to build some documentation about them for potential future use, and quite a few of them are not displaying correctly. I captured the exception message on attempting to display the hachibee theme. It is below. I hope this is both helpful and timely. Hopefully whatever is causing this one not to display is in common with the others. Probably 50-60% of them WERE displaying correctly.

======================================== stderr ========================================
/opt/hostedtoolcache/Python/3.10.14/x64/lib/python3.10/urllib/parse.py:docstring of urllib.parse.quote:13: ERROR: Unexpected indentation. [docutils]
/home/runner/work/sphinx-themes.org/sphinx-themes.org/sample-docs/kitchen-sink/blocks.rst:138: WARNING: Include file '/home/runner/work/sphinx-themes.org/src/furo/__init__.py' not found or reading it failed [docutils]
/home/runner/work/sphinx-themes.org/sphinx-themes.org/sample-docs/kitchen-sink/lists.rst:202: WARNING: Include file '/home/runner/work/sphinx-themes.org/src/furo/__init__.py' not found or reading it failed [docutils]

Traceback (most recent call last):
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 1160, in handle_page
    output = self.templates.render(templatename, ctx)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/jinja2glue.py", line 201, in render
    return self.environment.get_template(template).render(context)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/jinja2/environment.py", line 1304, in render
    self.environment.handle_exception()
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/jinja2/environment.py", line 939, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/hachibee_sphinx_theme/hachibee/page.html", line 1, in top-level template code
    {% extends "!layout.html" %}
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/hachibee_sphinx_theme/hachibee/layout.html", line 134, in top-level template code
    {{ css() }}
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/jinja2/sandbox.py", line 394, in call
    return __context.call(__obj, *args, **kwargs)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/jinja2/runtime.py", line 782, in _invoke
    rv = self._func(*arguments)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/hachibee_sphinx_theme/hachibee/layout.html", line 95, in template
    <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css" />
jinja2.exceptions.UndefinedError: 'style' is undefined

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

Traceback (most recent call last):
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/cmd/build.py", line 337, in build_main
    app.build(args.force_all, args.filenames)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/application.py", line 378, in build
    self.builder.build_update()
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/__init__.py", line 296, in build_update
    self.build(to_build,
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/__init__.py", line 366, in build
    self.write(docnames, list(updated_docnames), method)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/__init__.py", line 613, in write
    self._write_serial(sorted(docnames))
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/__init__.py", line 623, in _write_serial
    self.write_doc(docname, doctree)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 675, in write_doc
    self.handle_page(docname, ctx, event_arg=doctree)
  File "/home/runner/work/sphinx-themes.org/sphinx-themes.org/build/hachibee-sphinx-theme/lib/python3.10/site-packages/sphinx/builders/html/__init__.py", line 1167, in handle_page
    raise ThemeError(__("An error happened in rendering the page %s.\nReason: %r") %
sphinx.errors.ThemeError: An error happened in rendering the page index.
Reason: UndefinedError("'style' is undefined")

Theme error:
An error happened in rendering the page index.
Reason: UndefinedError("'style' is undefined")

Kind regards,
Vic

[pradyunsg]

The issue is that those themes are not compatible with the latest version of Sphinx and, fundamentally, pip install <that theme package> will result in a failing build with that exact message.

This is not a problem with this site but rather a problem with those projects.

[pradyunsg]

I'm gonna go ahead and close this as something that we can't really fix, but I'll also pin this for visibility for the next person who comes wondering about this.

[vwheeler63]

This is not a problem with this site but rather a problem with those projects.

Ah! Thanks for the clarification! Hopefully the authors will fix them in a hurry! :-)

Also thank you for making the title more accurate. I just realized I could see "Build Failed" in the high-level theme display, and I re-computed my 40% -- should have been 23.5%. 12 out of 51. :-) Anyway you fixed it.

And by the way, https://sphinx-themes.org/ is a brilliant display, especially the Kitchen Sink page groups -- very nice way for people to "shop" before they install.... It must have taken a lot of work to put that together!