Two changes (here we go again :-( ). 1) The __builtins__ variable in the __main__ module is set to the __builtin__ module instead of its __dict__. 2) Get rid of the SIGHUP and SIGTERM handlers. They can't be made to work reliably when threads may be in use, they are Unix specific, and Python programmers can now program this functionality is a safer way using the signal module.