Hi Ondrey, newer astropy (>= 3.x) is limited to Python 3.x, and the problem appears only with Python 2.7. The "python-astropy" package mentioned in the Affects field of the bug is the stable (but supported) version 2.0.x, which is (now) Python-2 only. The other packages mentioned there support both Python branches, and there only Python 2 is affected.
By reading the upstream changelog, I could not find a cause what should cause the incompatibility. Also, the logs now all contain a warning like /usr/lib/python2.7/dist-packages/_pytest/cacheprovider.py:58 /usr/lib/python2.7/dist-packages/_pytest/cacheprovider.py:58: PytestWarning: could not create cache path /usr/lib/python2.7/dist-packages/aplpy/.pytest_cache/v/cache/nodeids PytestWarning(fmt.format(**args) if args else fmt), self._config which is not present in the Python 3 runs (and also not with pytest 3.6.4) -- this shows that probably something goes wrong when using pytest/Python2 on installed packages. For python-m3u8, the CI test is a simple m3u8.loads() call that does not invoke pytest at all. Best Ole