Error: Unknow Group When Mannually Assign Topic

[jesseXu]

According the kafka documentation if I use assign instead of subscribe method, I don't need to set a group id, but I got the following error:

Can't subscribe to specified topics: KafkaError (Subscription error: Local: Unknown group)

[jesseXu]

It seems I have to fetch the metadata first to make the data available on local then probably I won't the this issue.