'If the config file is not writeable a meaningful response is
written.'

@skip_on_broken_permissions
def test_no_permission(self):

    path = FilePath(self.mktemp())
    path.makedirs()
    path.chmod(0)
    self.addCleanup(path.chmod, 511)
    config = path.child('out.json')
    with attempt_effective_uid('nobody', suppress_errors=True):
        result = run_expecting_error('--config', config.path)
    self.assertEqual(result, ('Writing    config    file    %s    failed:    Permission    denied\n' % (config.path,)))
