Got the memory fault! Seems that top let forms in macros may be
evaluated in a different processing mode. Dont entirely under this
but basically if I try and put the initialise call in an 'if' as a top
level form it throws a memory error, if I call the initializer from
inside the pipeline func at runtime it always works....Damn!

I will find a way to fix this but I'm just happy I can compile properly
and that I can now focus on testing the new shader constructs.