'make_tmpfs_mount errors with a ``MakeTmpfsMountError`` if the mount
point does not exist.'

def test_make_tmpfs_mount_failure(self):

    non_existent = self._get_directory_for_mount().child('non_existent')
    with ExpectedException(MakeTmpfsMountError, '.*non_existent.*'):
        self.manager_under_test.make_tmpfs_mount(non_existent)
