Comment 4 for bug 1501805

Yeah, our build system is somewhat broken. It's from very early when Python 3 support was introduced and just hacked to make work with new changed.

I did not catch the stderr thing, as it is not shown by default in normal testing environments. I can adjust the tests to check the deprecation marking, instead of just printing it, that would make much more sense.

I requires a construct roughly like:

        with warnings.catch_warnings(record=True) as caught_warnings:
            warnings.simplefilter("always")
           ... <code raising warning> ...

        self.assertEqual(len(caught_warnings), 1)
        self.assertTrue(issubclass(caught_warnings[0].category,
                                   DeprecationWarning))