On the main branch, on both Windows and Linux, this crashes:

class Thing: pass thing = Thing() for i in range(10): print(i) try: str.upper(thing) except TypeError: pass print("ok")

Other methods like str.split, bytes.split, and list.sort fail similarly. I caught this by running

./python -m test test_descr -m test_proxy_call -R3:20 

Looking through stack traces, it appears the failure is on the res = cfunc(...) call in PRECALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS instruction. It looks to be a 3.11-only bug.