mock.patch.object ... autospec=True does not work

[sdague]

def test_serialized_with_retry_socket_reset_reraised(self):
    exc = socket.error()
    exc.errno = errno.ECONNRESET
    plugin = 'glance'
    fn = 'download_vhd'
    num_retries = 1
    callback = None
    retry_cb = mock.Mock()
    with mock.patch.object(self.session, 'call_plugin_serialized',
            autospec=True) as call_plugin_serialized:
        call_plugin_serialized.side_effect = exc
        self.assertRaises(exception.PluginRetriesExceeded,
                self.session.call_plugin_serialized_with_retry, plugin, fn,
                num_retries, callback, retry_cb)
        call_plugin_serialized.assert_called_with(plugin, fn)
        self.assertEqual(2, call_plugin_serialized.call_count)

From https://github.com/openstack/nova/blob/master/nova/tests/unit/virt/xenapi/client/test_session.py#L143-L158

No longer works.

The current work around is change 'autospec' to 'spec'. Not sure the root issue, lifeless sorted out the fix. This bug is here for tracking the resolution.

[dtantsur]

Here is my reproducer for the failure: http://fpaste.org/242638/
Note that with spec=True method signature is not checked, so it's not literal replacement.

I was told by someone that the same regression happened between Python 3.4.0 and 3.4.2.

[rbtcollins]

This was reported upstream as http://bugs.python.org/issue23661 and I'm applying the patch and backporting now.

[rbtcollins]

Fixed in Python 3.6 and in mock 1.1.3 [backwards compat bugfix].