bpo-32294: Fix multiprocessing test_semaphore_tracker() (GH-4885) (#4887)

Run the child process with -E option to ignore the PYTHONWARNINGS
environment variable.
(cherry picked from commit 9402c8367bf6ada1b84f620ad957750c33adbaf9)

diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
index 774e797f02eb36c6b20497bdcc2a875b0de6de29..e4d60f8804269d4614df14e2cde863a5e4819454 100644 (file)
--- a/Lib/test/_test_multiprocessing.py
+++ b/Lib/test/_test_multiprocessing.py
@@ -4146,7 +4146,7 @@ class TestSemaphoreTracker(unittest.TestCase):
         '''
         r, w = os.pipe()
         p = subprocess.Popen([sys.executable,
-                             '-c', cmd % (w, w)],
+                             '-E', '-c', cmd % (w, w)],
                              pass_fds=[w],
                              stderr=subprocess.PIPE)
         os.close(w)