I'll commit tonight.  BTW, on a without-threads build:


>>> import dummy_threading
>>> dummy_threading.settrace
>>> dummy_threading.settrace.__module__
'threading'

In other words, dummy_threading.settrace is always the same as threading.settrace. Since threading.settrace just sets a global variable which is probably not used by dummy_threading, OP's patch is probably fine, but may not be as future proof.