Machete-mode debugging, ala https://www.youtube.com/watch?v=bAcfPzxB3dk.

matchete_mode.py

        # td is a TemporaryDirectory that's being deleted earlier than
        # expected somewhere in my test suite.
        import shutil
        old_rmtree = shutil.rmtree

        def rmtree(path, *args, **kwargs):
            if path == td.name:
                import nose.tools; nose.tools.set_trace()
            return old_rmtree(path, *args, **kwargs)

        shutil.rmtree = rmtree