> Overall it looks as if the the Azure pipeline should be fixed, though. It's not ideal that the tests pass while running the PR, but not in other situations.

I agree. This specific test only seems to run *after* a commit is made. I don't see a way to run this test on a PR, even the `test-with-buildbots` test doesn't seem to trigger it.

> Also, the warnings suppression is not really obvious.

Yup, it's hidden away in the docs here, so I was rather lost too: https://docs.python.org/3/library/warnings.html#testing-warnings

Anyways, I'm not actually sure that the PR will fix it. AFAICS, the only way to test it is to commit it and let the buildbot run ;). I can't reproduce it locally.