test_concurrent_futures.test_deadlock fails with env changed: sys.stderr was modified on s390x RHEL8 Refleaks 3.x #109832
Description
s390x RHEL8 Refleaks 3.x:
Warning -- sys.stderr was modified by test.test_concurrent_futures.test_deadlock
Warning -- Before: <_io.TextIOWrapper name='<stderr>' mode='w' encoding='utf-8'>
Warning -- After: <_io.StringIO object at 0x3ff971b6410>
build: https://buildbot.python.org/all/#/builders/75/builds/895