Guard against possible slow test

Author: giampaolo

Lib/test/test_subprocess.py

@@ -4150,8 +4150,11 @@ def assert_wait_race_condition(self, patch_target, real_func):
 
         def wrapper(*args, **kwargs):
             ret = real_func(*args, **kwargs)
-            os.kill(p.pid, signal.SIGTERM)
-            os.waitpid(p.pid, 0)
+            try:
+                os.kill(p.pid, signal.SIGTERM)
+                os.waitpid(p.pid, 0)
+            except OSError:
+                pass
             return ret
 
         with mock.patch(patch_target, side_effect=wrapper) as m: