build: remove dependency on Python sass module

[kdmccormick]

Supporting information

Depends on:

• build: compile/watch sass with new npm scripts #34318

Part of:

• [DEPR]: Asset processing in Paver #31895

Description

Instead of using libsass-python's sass module, which is incompatible
with Python 3.11, we now skip through to libsass-python's _sass module,
which directly binds to the underlying C++ libsass library.

This ensures that the Sass build will not a blocker for the edx-platform
Python 3.11 upgrade, which needs to land in Redwood.

For more details, see the docstring at scripts/compile_sass.py#L167

Testing

Same as #34318 (comment)

Merge considerations

None

[feanil]

Looks good to me, I was able to build the assets and load the site on Node 16.10

[kdmccormick]

Thanks @feanil , do I have your thumbs up on the prerequisite PR too? #34318

[open-craft-grove]

Sandbox deployment successful 🚀
🎓 LMS
📝 Studio
ℹ️ Grove Config, Tutor Config, Tutor Requirements

[open-craft-grove]

Sandbox deployment successful 🚀
🎓 LMS
📝 Studio
ℹ️ Grove Config, Tutor Config, Tutor Requirements

[dianakhuang]

Stuck in a meeting so can't verify that this is the source, but it seems likely, but we're seeing this error in our builds:

Traceback (most recent call last):
  File "scripts/compile_sass.py", line 505, in <module>
    main(prog_name="npm run compile-sass --")
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.8/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.8/site-packages/click/core.py", line 1078, in main
    rv = self.invoke(ctx)
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.8/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.8/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.8/site-packages/click/decorators.py", line 33, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "scripts/compile_sass.py", line 411, in main
    compile_sass_dir(
  File "scripts/compile_sass.py", line 262, in compile_sass_dir
    for sass_path in glob.glob(str(source) + "/**/*.scss"):
UnboundLocalError: local variable 'source' referenced before assignment

[kdmccormick]

@dianakhuang Oof, seems likely, feel free to merge #34476

[kdmccormick]

Yup, the issue is on this line, I should have changed source to source_root. This made it through my local testing because source is a local variable in the new loop above this one, which was erroneously being used here, leading a silent failure.

I imagine that 2U must have a theme without any matched scss files, meaning that the local source variable is never assigned, leading a to a loud failure instead in their pipelines instead of a quiet one.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.