Comment 2 for bug 250764

I did this in subunit, but should be directly portable to testtools (any reason subunit.run doesn't
just call testtools.run?)

With a small patch they can support --discover using the discover package.

When this argument is given they just use the discover module to find tests, with
the load_tests API being used (it doesn't support test_suite) if it is there.

That requires re-implementing parts of unittest.TestProgram that is currently
used, as that doesn't support passing a testsuite.

See https://code.edge.launchpad.net/~james-w/subunit/discovery/+merge/26893

Thanks,

James