test_notification_poller_requeues_when_busy drained and reused the
process-global process_registry.completion_queue, so a concurrent test
in the same xdist worker could put/get on the shared singleton mid-run
and empty the event the poller requeues — flaking 'assert not
completion_queue.empty()' under parallel CI load only.
Monkeypatch a fresh Queue onto the singleton for the test's duration so
nothing external can interleave. The poller reads completion_queue by
attribute at runtime, so the isolated queue is what it operates on.
monkeypatch restores the original on teardown. Verified immune: 50/50
passes under a background thread hammering the global queue.
teknium1
4fd8521e44