codecov coverage dropped

[dcherian]

Looks like something went wrong when #4408 was merged (23dc2fc)

[mathause]

Possibly https://pytest-cov.readthedocs.io/en/latest/config.html#caveats

(Because the PR adds tmpdir.chdir() and the caveats mention chdir)

[mathause]

tmpdir.chdir() is the issue. I think it then gets the paths wrong... But I don't know yet what to do about it.