Projects using conda don't show all packages installed (and IPython CSS is broken)

[astrojuanlu]

This tweet by @Carreau caught my attention:

https://twitter.com/Mbussonn/status/1454253505724649472

Yes, css broken. I don't know why, but enough for today.

And indeed, it looks like IPython is experiencing readthedocs/sphinx_rtd_theme#1115:

• Good ✔️ https://ipython.readthedocs.io/en/7.23.1/whatsnew/version7.html#ipython-7-23 (build https://readthedocs.org/projects/ipython/builds/13687131/)
• Bad ❌ https://ipython.readthedocs.io/en/7.24.0/whatsnew/version7.html#ipython-7-23-and-7-23-1 (build https://readthedocs.org/projects/ipython/builds/13879122/)

And recent builds also exhibit this behavior, see https://readthedocs.org/projects/ipython/builds/15133660/.

Clearly docutils 0.17 is being used now, but I would expect sphinx_rtd_theme to have addressed the incompatibility. Yet, there is no way to know what version of the theme is getting installed in each build, since the conda env create has the --quiet flag, and only shows the pip part.

[stsewd]

We have a feature flag for that

readthedocs.org/readthedocs/projects/models.py

Line 1667 in f38fe0f

LIST_PACKAGES_INSTALLED_ENV = 'list_packages_installed_env'

. See also #7005

[astrojuanlu]

Enabled the flag for IPython and triggered a latest build https://readthedocs.org/projects/ipython/builds/15221374/

The culprit seems to be a old version of sphinx_rtd_theme:

conda list --name latest
# packages in environment at /home/docs/checkouts/readthedocs.org/user_builds/ipython/conda/latest:
#
# Name                    Version                   Build  Channel
...
docutils                  0.17.1           py38h06a4308_1  
...
sphinx                    4.2.0              pyhd3eb1b0_1  
sphinx_rtd_theme          0.4.3              pyhd3eb1b0_0  
...

[astrojuanlu]

Attempt to fix at ipython/ipython#13261

[astrojuanlu]

We have a feature flag for that

Is there a reason to not have LIST_PACKAGES_INSTALLED_ENV enabled by default? cc @agjohnson

[stsewd]

This is comment linked on the other issue #6992 (comment)

[astrojuanlu]

This is a known issue then, and the support request has been addressed. Closing.