--subunit makes --until-failure not actually work

[Sean Dague]

If you specify the --subunit flag to testr run, --until-failure no longer fails correctly.

This can be reproduced with a trivial case of:

self.assertTrue(False)

in some test, then

testr run --subunit --until-failure that_test_name

It will loop forever with no stopping.

[Matthew Treinish (treinish)]

I was playing with the --subunit flag a bit today and found that using --subunit means that testr is always returning 0 even during failure. I was going to file a separate bug for that, but I expect that these 2 issues are in fact the same.

[Robert Collins (lifeless)]

--subunit should always return 0, because the intent of --subunit is that you're doing your own porcelain {it will return non-zero on stream generation failure}.

--until-failure is awkward, but I think making it loop sanely with --subunit is better than making the options incompatible with each other.