fix possible error

diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index d0316073cb55bbfaadddeed85ed94699c4b6e3d5..c6a5cf49d2a1e47c86b4c4dda3256df8db8c9bbb 100644 (file)
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -329,7 +329,10 @@ class ThreadTests(unittest.TestCase):
 
         t = threading.Thread()
         with catch_warning() as w:
-            del threading.__warningregistry__
+            try:
+                del threading.__warningregistry__
+            except AttributeError:
+                pass
             msg = "isDaemon() is deprecated in favor of the " \
                   "Thread.daemon property"
             check(t.isDaemon(), w, msg)