Sabotage rexec.py.  It is not safe since the new-style classes.
diff --git a/Lib/Bastion.py b/Lib/Bastion.py
index 99990a2..ae2db74 100644
--- a/Lib/Bastion.py
+++ b/Lib/Bastion.py
@@ -97,6 +97,8 @@
 
     """
 
+    raise RuntimeError, "This code is not secure in Python 2.2 and 2.3"
+
     # Note: we define *two* ad-hoc functions here, get1 and get2.
     # Both are intended to be called in the same way: get(name).
     # It is clear that the real work (getting the attribute