I attempted to fix this in ed3097197063ebda4a85a80de0cc4a1abd959376. I think it may be a compiler bug, it compiles fine with 4.5. Let me know if this change *causes* problems for anyone.
I'm sorry but it stills failing I will find some time this week to have a look but I can't at the moment. Thanks for your reply.
It only happens in my branch. I think it is caused by some missing import.