Great, thanks! There are actually a couple of other issues with the swipl package too, if you feel like looking at them (otherwise I will create a patch at some point): (1) it needs $secondaryArchSuffix removed from the cmd provides lines (or you end up with swipl-x86 which doesn't make much sense for this). I think I followed an old convention that is no longer used (except where it makes sense like for build tools). (2) The architectures line is also wrong: it doesn't build with gcc2.
EDIT: Sorry I just read this properly, you're not talking about the SWI Prolog package, are you? For clarity, I wasn't talking about your picat package... think we have crossed lines (I will fix swipl)