From e2e02dd86c56f8ecdeec702d19d563c23900c378 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(). (cherry picked from commit 40c8edd2ca1e8df67ae8a5f02a660ff3ce1f061b) Co-authored-by: Davi de Jesus --- 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 ba0659a349808ef..827f1b6603050a6 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -972,7 +972,9 @@ def check_forkserver_death(self, signum): 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):