On Py3k, -tt and -3 are no-op and unsupported respectively.
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 92d1597..83c9928 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -3,7 +3,7 @@
"""
Usage:
-python -m test.regrtest [options] [test_name1 [test_name2 ...]]
+python -m test [options] [test_name1 [test_name2 ...]]
python path/to/Lib/test/regrtest.py [options] [test_name1 [test_name2 ...]]
@@ -14,7 +14,7 @@
For more rigorous testing, it is useful to use the following
command line:
-python -E -tt -Wd -3 -m test.regrtest [options] [test_name1 ...]
+python -E -Wd -m test [options] [test_name1 ...]
Options: