readthedocs.org: API to get active versions is slow, when injecting the sphinx context

Details

• Read the Docs project URL: https://docxtemplater.readthedocs.io/en/latest/goals.html
• Build URL (if applicable): https://readthedocs.org/api/v2/build/10386322.txt
• Read the Docs username (if applicable): edi9999

Expected Result

I expect the build to succeed (or to fail with a clearer error message)

Actual Result

The build stopped after 40 seconds, just after doing following command :

/home/docs/checkouts/readthedocs.org/user_builds/docxtemplater/envs/latest/bin/python -m pip install --upgrade --cache-dir /home/docs/checkouts/readthedocs.org/user_builds/docxtemplater/.cache/pip Pygments==2.3.1 setuptools==41.0.1 docutils==0.14 mock==1.0.1 pillow==5.4.1 alabaster>=0.7,<0.8,!=0.7.5 commonmark==0.8.1 recommonmark==0.5.0 sphinx<2 sphinx-rtd-theme<0.5 readthedocs-sphinx-ext<1.1

I think this might be related to https://github.com/readthedocs/readthedocs.org/issues/6687, but I would like to keep older versions available in the doc if possible.

Also, if it can help, the last successful build for my project was on 2020-01-31T10:34:03.130141Z : https://readthedocs.org/api/v2/build/10360658.txt and the first failing build was on 2020-02-05T08:40:45.500491Z https://readthedocs.org/api/v2/build/10386322.txt.

The logs inside both these builds seem to be quite different, for example, the successful build does the following :

git remote set-url origin https://github.com/open-xml-templating/docxtemplater.git
git fetch origin --force --tags --prune --prune-tags --depth 50
git checkout --force origin/master

The failing build does the following :

git clone --no-single-branch --depth 50 https://github.com/open-xml-templating/docxtemplater.git .
git checkout --force origin/master
git clean -d -f -f

So I suspect there might have been a big change in readthedocs between those two dates (or something else happened which I don’t understand).