c.f. this Twisted ticket: http://twistedmatrix.com/trac/ticket/3703

Twisted's test tool has an extended TestCase which uses the 'skip'
attribute, on both tests and methods, to determine whether to skip them.
 You can see the implementation here:

http://twistedmatrix.com/trac/browser/trunk/twisted/trial/unittest.py?rev=26043#L655

The addition of the new 'skip' method in unittest.py therefore causes
trial, twisted's test tool, to unconditionally skip all tests.

I've set the priority to release blocker because I'd like it to be
determined whether this is really python's fault, or twisted's fault for
subclassing TestCase.

If the new 'skip' method of TestCase is renamed to something else, say
skipTest, this won't be a problem.

While I understand that this is technically a compatible change (the
addition of an attribute) I'd appreciate it if this changed on Python's
side of things, because leaving it up to Twisted means we need to go
through a deprecation cycle on a long-standing, stable public interface
that a lot of test code is using.