From 40c8edd2ca1e8df67ae8a5f02a660ff3ce1f061b Mon Sep 17 00:00:00 2001 From: Davi de Jesus Date: Fri, 23 Oct 2026 18:19:57 -0300 Subject: [PATCH] gh-160295: Fix race in test_forkserver_sigkill (GH-160296) After a SIGKILL, the forkserver can no longer report the first child's exit status, so proc.join() returns with exit code 255 while the child may still be running. Wait for the event instead of checking it right after join(). --- Lib/test/_test_multiprocessing.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py index 00de9d0ac92..d267c9d3dfa 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -994,7 +994,9 @@ class _TestProcess(BaseTestCase): self.assertEqual(proc2.exitcode, 0) proc.join() - self.assertTrue(evt.is_set()) + # After SIGKILL, join() can return (exitcode 255) as soon as the + # status pipe is closed, before the orphaned child has run. + self.assertTrue(evt.wait(support.SHORT_TIMEOUT)) self.assertIn(proc.exitcode, (0, 255)) def test_forkserver_sigint(self):