Hi, This was sent to the Debian BTS: https://bugs.debian.org/1009112 This issue was reported upstream: https://github.com/eventlet/eventlet/issues/730 https://github.com/eventlet/eventlet/issues/739 For #730, I tried manually, indeed: # python3.9 tests/isolated/patcher_existing_locks_locked.py pass # python3.10 tests/isolated/patcher_existing_locks_locked.py Traceback (most recent call last): File "/root/eventlet/python-eventlet-0.30.2/tests/isolated/patcher_existing_locks_locked.py", line 19, in <module> lock.release() RuntimeError: cannot release un-acquired lock I don't understand what's going on. Can anyone help? Cheers, Thomas Goirand (zigo)