Index: Lib/test/regrtest.py
===================================================================
--- Lib/test/regrtest.py	(revision 84775)
+++ Lib/test/regrtest.py	(working copy)
@@ -1458,6 +1458,10 @@
         return self.expected
 
 if __name__ == '__main__':
+    # In some cases __file__ is relative.
+    # For example when running trace or profile.  See bug #9323.
+    __file__ = os.path.abspath(__file__)
+
     # Simplification for findtestdir().
     assert __file__ == os.path.abspath(sys.argv[0])