I think this just can`t work:
https://github.com/zendframework/zend-cache/blob/master/src/Storage/Adapter/AbstractAdapter.php#L193
https://github.com/zendframework/zend-eventmanager/blob/release-2.6.2/src/EventManager.php#L57

BTW, I'm not offending, just complaining, with the v3 oncoming this backward compatibility issues got worse directly, into masters. You know I can`t be happy with things like that. Spending time finding BC breaks in the ZF2 instead of doing work for my clients. I really appreciate your work but this is sad for me that the ZF2 is going like this.