Wow. I love Devel::Size, I've used that module to test production code many times. Thank you so much for such a useful module. I'm pretty sure my approach is incompatible with exceptions, as I do all my work in the typemap, and I use the XS to directly map to my target function. What I "should" be doing is creating an insulating class, that can catch the exception at the XS layer, and then rethrowing the perl exception from there. This is basically what you are doing in your code. I still think this is unfortunate. You'd think there would be some handy macro that would handle this sort of thing for you.