TST: CircleCI 32-bit job is broken

[pllim]

Example log from master: https://circleci.com/gh/astropy/astropy/35792

There are 96 failures. One of them:

astropy/coordinates/tests/test_frames.py:522: AssertionError
______________________________ test_dynamic_attrs ______________________________
[gw3] linux -- Python 3.5.7 /opt/python/cp35-cp35m/bin/python

    def test_dynamic_attrs():
        from astropy.coordinates.builtin_frames import ICRS
        c = ICRS(1*u.deg, 2*u.deg)
        assert 'ra' in dir(c)
        assert 'dec' in dir(c)
    
        with pytest.raises(AttributeError) as err:
            c.blahblah
>       assert "object has no attribute 'blahblah'" in str(err)
E       assert "object has no attribute 'blahblah'" in '<ExceptionInfo AttributeError tblen=2>'
E        +  where '<ExceptionInfo AttributeError tblen=2>' = str(<ExceptionInfo AttributeError tblen=2>)

[pllim]

Could be related to pytest 5.0 release if they changed the str(e) behavior when you catch the exception in pytest.raises(). To test that theory, you can roll back to pytest 4.x series in 32-bit container and see if the tests pass again. 🤷‍♀

[dhomeier]

This seems to be the relevant change. Looks like the solution would be to substitute with str(e.value).
I've tested this on a local pytest 5.0.0 installation, which raised the same errors for test_angles.py, and it did work (and also works back with pytest 3.10.1).

A quick grep shows that 63 of our tests already have that syntax, which only leaves 90-119 to fix (not sure about the 20-something that do not appear to throw errors). 💯

[bsipocz]

Thank you @dhomeier. Since you've already made the changes, would you mind opening a PR?