Fail on x86 Gentoo Refleaks 3.x:
https://buildbot.python.org/all/#/builders/1/builds/618

3:15:59 load avg: 6.93 [339/423/1] test__xxsubinterpreters failed -- running: test_multiprocessing_spawn (19 min 36 sec)
beginning 6 repetitions
123456
.Exception in thread Thread-17:
Traceback (most recent call last):
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/threading.py", line 923, in _bootstrap_inner
    self.run()
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/threading.py", line 865, in run
    self._target(*self._args, **self._kwargs)
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/test/test__xxsubinterpreters.py", line 51, in run
    interpreters.run_string(interp, dedent(f"""
RuntimeError: unrecognized interpreter ID 108
test test__xxsubinterpreters failed -- Traceback (most recent call last):
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/test/test__xxsubinterpreters.py", line 765, in test_still_running
    interpreters.destroy(interp)
AssertionError: RuntimeError not raised

(...)

test_after_destroying (test.test__xxsubinterpreters.ListAllTests) ... ok
test_initial (test.test__xxsubinterpreters.ListAllTests) ... ok
test_SystemExit (test.test__xxsubinterpreters.RunStringTests) ... ok
test_already_running (test.test__xxsubinterpreters.RunStringTests) ... spam
Exception in thread Thread-31:
Traceback (most recent call last):
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/threading.py", line 923, in _bootstrap_inner
    self.run()
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/threading.py", line 865, in run
    self._target(*self._args, **self._kwargs)
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/test/test__xxsubinterpreters.py", line 51, in run
    interpreters.run_string(interp, dedent(f"""
RuntimeError: unrecognized interpreter ID 190
FAIL
test_bad_id (test.test__xxsubinterpreters.RunStringTests) ... ok
test_bad_script (test.test__xxsubinterpreters.RunStringTests) ... ok
test_bytes_for_script (test.test__xxsubinterpreters.RunStringTests) ... ok
test_create_thread (test.test__xxsubinterpreters.RunStringTests) ... ok
test_does_not_exist (test.test__xxsubinterpreters.RunStringTests) ... ok
test_error_id (test.test__xxsubinterpreters.RunStringTests) ... ok
test_execution_namespace_is_main (test.test__xxsubinterpreters.RunStringTests) ... ok
test_failure (test.test__xxsubinterpreters.RunStringTests) ... ok
test_fork (test.test__xxsubinterpreters.RunStringTests) ... ok
test_in_thread (test.test__xxsubinterpreters.RunStringTests) ... ok
test_invalid_syntax (test.test__xxsubinterpreters.RunStringTests) ... ok
test_main_reused (test.test__xxsubinterpreters.RunStringTests) ... ok
test_shared_overwrites (test.test__xxsubinterpreters.RunStringTests) ... ok
test_shared_overwrites_default_vars (test.test__xxsubinterpreters.RunStringTests) ... ok
test_still_running_at_exit (test.test__xxsubinterpreters.RunStringTests) ... skipped 'blocking forever'
test_success (test.test__xxsubinterpreters.RunStringTests) ... ok
test_sys_exit (test.test__xxsubinterpreters.RunStringTests) ... ok
test_with_shared (test.test__xxsubinterpreters.RunStringTests) ... ok
test_bytes (test.test__xxsubinterpreters.ShareableTypeTests) ... ok
test_int (test.test__xxsubinterpreters.ShareableTypeTests) ... ok
test_non_shareable_int (test.test__xxsubinterpreters.ShareableTypeTests) ... ok
test_singletons (test.test__xxsubinterpreters.ShareableTypeTests) ... ok
test_types (test.test__xxsubinterpreters.ShareableTypeTests) ... ok

======================================================================
FAIL: test_already_running (test.test__xxsubinterpreters.RunStringTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/buildbot/buildarea/cpython/3.x.ware-gentoo-x86.refleak/build/Lib/test/test__xxsubinterpreters.py", line 855, in test_already_running
    interpreters.run_string(self.id, 'print("spam")')
AssertionError: RuntimeError not raised