Logged In: YES 
user_id=21627

Tim, I'm not surprised that raising SystemExit in a thread
fails to exit Python; the reason simply is that
threadmodule.c:t_bootstrap choses to ignore
PyExc_SystemExit, when it instead should invoke
PyErr_PrintEx instead.

The bug is obviously that exit_thread also raises
SystemExit, when people apparently really want sys.exit and
thread.exit to be two different things. So I think
thread.exit should raise ThreadExit, and raising SystemExit
in a thread should cause Py_Exit to be invoked (along with
all other necessary cleanup). In short, 2.12 of
threadmodule.c was wrong, IMO.