Index: Lib/test/regrtest.py
===================================================================
--- Lib/test/regrtest.py	(révision 80600)
+++ Lib/test/regrtest.py	(copie de travail)
@@ -1460,6 +1460,10 @@
         return self.expected
 
 if __name__ == '__main__':
+    # Ensure that regrtest.py is called with -bb python option
+    if sys.flags.bytes_warning < 2:
+        os.execv(sys.executable, [sys.executable, '-bb'] + sys.argv)
+
     # Simplification for findtestdir().
     assert __file__ == os.path.abspath(sys.argv[0])