test_protocol fails intermittently on OSX 10.8, reason unknown.
Edit Modules/objc/objc-runtime-compat.h and disable the #define for protocol_getMethodDescription
Build and install
Run PyObjCTest/test_protocol.py a number of times
On my machine this fails at least once in 10 runs of the tests.
As a workaround I've added a wrapper for protocol_getMethodDescription to the runtime compatibility file. That workaround is almost certainly the wrong solution though, hence this tracker item.