Learning rule with two error signals

Is there currently a way to write a learning that gets two different error signals as input?

You could pull this commit from the generic learning rule PR, which allowed learning rules to define arbitrary size_in.

That doesn’t seem to work properly because the size_in also defines one dimension of the the delta signal (which is different).

In case anyone else is reading this and looking for that functionality: I put together an implementation in nengo/nengo#1307.