docs builds are failing mysteriously

[d-v-b]

I noticed in #2795 that the docs builds were failing. The error messages look like this:

[AutoAPI] Reading files... [  2%] /home/docs/checkouts/readthedocs.org/user_builds/zarr/checkouts/2795/src/zarr/_version.py
WARNING: Unable to read file: /home/docs/checkouts/readthedocs.org/user_builds/zarr/checkouts/2795/src/zarr/_version.py [autoapi.not_readable]
[AutoAPI] Reading files... [  3%] /home/docs/checkouts/readthedocs.org/user_builds/zarr/checkouts/2795/src/zarr/creation.py
WARNING: Unable to read file: /home/docs/checkouts/readthedocs.org/user_builds/zarr/checkouts/2795/src/zarr/creation.py [autoapi.not_readable]

This is consistent with RTD not setting up our project correctly.

I created #2796 to check if these failures were due to changes I made in #2795, and it seems like the answer to that is "no", so something must have changed about the build process.

Does anyone have ideas for why the docs builds are failing, and how we might fix it?

[dstansby]

I diffed the last passing build log, and first failing build log, and differences in dependencies being installed are:

• astroid (looks like we're now picking up an alpha release!)
• beautifulsoup4 (a micro version bump)

So I'd suggest a good next debugging step would be pinning astroid<4 and see if that works? If it does it's something that eventually needs fixing upstream in sphinx-autoapi, because that's where it's being pulled as a dependency.

[d-v-b]

closed by #2796