I’m not an expert on Sphinx. Maybe <http://www.sphinx-doc.org/en/stable/config.html#confval-suppress_warnings> could help with disabling these warnings. Considering there are so many false positives, it might be best to disable the warning. Though my patch does have a few genuine improvements as well.

I already used the :option:`-Wd <-W>` syntax in some cases; see Doc/library/warnings.rst for example. The problem in unittest.rst is I think Sphinx is trying to find a -W option defined within unittest.rst (with the unittest --buffer etc options), rather than the main Python options from using/cmdline.rst.