Name of Failure:

test.test_subinterpreters.TestSubinterpreters.test_subinterpreters fails on every
Python 3.14 and 3.15 task on the green-gevent-rhel8 variant. 1 of 4595 tests fails
per task.

Link to task:

https://spruce.corp.mongodb.com/task/mongo_python_driver_green_gevent_rhel8_test_standard_v8.0_python3.15_sync_noauth_nossl_standalone_4fb6cc8976794271147c5f60d2146b72a35be10f_26_10_14_21_46_42

All 7 failing tasks: https://spruce.corp.mongodb.com/version/mongo_python_driver_4fb6cc8976794271147c5f60d2146b72a35be10f/tasks

Context of when and why the failure occurred:

The variant first ran on 2026-10-09. The task has 0 passing runs of 14 since then (2
unscheduled runs excluded). Every failure took about 150 seconds. The same test passes
at the same revisions on the 15 other variants that run it. Both subinterpreters
connect and write, then time out waiting on a cross-interpreter queue.

Stack trace:

FAILURE: AssertionError: subinterpreters failed to run: [ExecutionFailed('concurrent.interpreters._queues.QueueEmpty: queue 3 is empty'), ExecutionFailed('concurrent.interpreters._queues.QueueEmpty: queue 3 is empty')] ()