Index: regrtest.py
===================================================================
--- regrtest.py	(revision 56338)
+++ regrtest.py	(working copy)
@@ -340,7 +340,7 @@
         for arg in args:
             if arg in stdtests:
                 stdtests.remove(arg)
-        nottests[:0] = args
+            nottests.insert(0, arg)
         args = []
     tests = tests or args or findtests(testdir, stdtests, nottests)
     if single: