I can confirm that the patch fixes the recursion problem if threading._VERBOSE is set to true, but the test Antoine mentioned hangs when the test suite is run.

_VERBOSE is an internal, undocumented facility, so perhaps the priority on this isn't really "high".

On the other hand, Antoine's patch takes things from non-functional to at least partially functional, so perhaps it is worth applying as is, pending someone figuring out where the test hang is coming from.

I looked in to this briefly, but I have no clue how to trigger this in a unit test, since it seems to happen when regrtest imports logging which imports threading, and appears to my threading-ignorant eyes to be tied to conditions that only exist at initial module import.