Exception: Q-object when x-json encoder enebled.

[Timur Kozhevnikov]

RequestError: ('Something goes wrong while sending request', EncodeError(RuntimeError("Django Q-objects does not supported by 'x-json' codec. For running with Q-objects use celery_rpc>0.16 on both sides and set 'x-rpc-json' as task serializer for client",),))

it seems impossible to do default value with empty Q object in filter sinature.