AMD64 RHEL8 Refleaks 3.x:
https://buildbot.python.org/all/#/builders/206/builds/13

The system load was quite high: 12.64.

0:23:25 load avg: 12.64 [283/420/1] test_faulthandler failed (1 min 7 sec) -- running: test_bz2 (8 min 20 sec), test_dbm (12 min 51 sec), test_asyncio (14 min 46 sec), test_mmap (9 min 3 sec), test_zipfile (13 min 9 sec), test_mailbox (8 min 49 sec), test_largefile (8 min 15 sec), test_shelve (19 min 51 sec)
beginning 6 repetitions
123456
.test test_faulthandler failed -- Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-x86_64.refleak/build/Lib/test/test_faulthandler.py", line 610, in test_dump_traceback_later_file
    self.check_dump_traceback_later(filename=filename)
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-x86_64.refleak/build/Lib/test/test_faulthandler.py", line 594, in check_dump_traceback_later
    self.assertRegex(trace, regex)
AssertionError: Regex didn't match: '^Timeout \\(0:00:00.500000\\)!\\nThread 0x[0-9a-f]+ \\(most recent call first\\):\\n  File "<string>", line 17 in func\n  File "<string>", line 26 in <module>$' not found in 'Timeout (0:00:00.500000)!\nThread 0x00007f69484b2740 (most recent call first):\n  File "<string>", line 18 in func\n  File "<string>", line 26 in <module>'

The test passed when re-run in verbose mode. So it may be related to the high system load while tests were run in parallel.