exit() is not sys.exit()

There is a difference between exit() and sys.exit(), the former closes sys.stdin (see site.py) which makes it impossible to debug tests that call it. This is aggravated by the fact that if one test calls it, sys.stdin is closed so any other attempt to debug a different test are screwed.

There is no other difference... both raise SystemExit otherwise.

https://docs.python.org/2/library/constants.html?highlight=exit#constants-added-by-the-site-module is clear:

"They are useful for the interactive interpreter shell and should not be used in programs."

I'll have a fix shortly available.