#17143: fix a missing import in the trace module.  Initial patch by Berker Peksag.
diff --git a/Lib/trace.py b/Lib/trace.py
index 317b5fd..c09b365 100644
--- a/Lib/trace.py
+++ b/Lib/trace.py
@@ -58,6 +58,7 @@
 import gc
 import dis
 import pickle
+from warnings import warn as _warn
 try:
     from time import monotonic as _time
 except ImportError: