did not get issue numbers in above: issue31160 and issue40094.

I waited a day, before posting - in the hope it would go away.

Also, I have been testing manually (no -j arguments) - and test_builtin passes when run manually. So, becoming hard to dissect and propose a "cure".

I have started with:

./python  ./Tools/scripts/run_tests.py -j 1 -u all -W --slowest --fail-env-changed --timeout=1200 -j2

and now see the test stalled:

0:39:41 running: test_builtin (5 min 14 sec)
0:40:11 running: test_builtin (5 min 44 sec)
0:40:41 running: test_builtin (6 min 14 sec)
0:41:11 running: test_builtin (6 min 44 sec)
0:41:41 running: test_builtin (7 min 14 sec)
0:42:11 running: test_builtin (7 min 44 sec)
0:42:41 running: test_builtin (8 min 14 sec)
0:43:11 running: test_builtin (8 min 44 sec)