unittest and threading

[Ross Boylan]

Is it safe to use unittest with threads?

In particular, if a unit test fails in some thread other than the one
that launched the test, will that information be captured properly?

A search of the net shows a suggestion that all failures must be
reported in the main thread, but I couldn't find anything definitive.

If it matters, I'm using CPython 2.7.

Thanks.  If you're using email, I'd appreciate a cc.
Ross Boylan