First problem is that Eric's original example is wrong - with a prim
named 'primGuy' he should have been doing not:-
> MyPlugin doPrimitive: 'innerLoopX:y:limit:' withArguments #(1 1 1)
> 
but 
MyPlugin doPrimitive: #primGuy withArguments #(1 1 1)

The problem with the proposed fix is that there is no trivial mapping fr
mthe name the primitive is given in the #primitive:parameters:....
message and the actual method name! Some variety of looking at all the
methods in the relevant class, seeing if they send #primitive: or
#primitive:parameters: (etc) and the working ou the argument for the
primitive name will be needed. Ugly.....