Ironically, given that I'd always been worried this would be the most finnicky compiler snap to create, it's actually the simplest package definition out of all the Big 3 ;-)
Without even having seen your snap file, I can confidently say that this is just due to the idiosyncrasies of the snap environment, though.
Oh wait, no, GDC is still stuck on an ancient C++-based frontend. Not too surprising, then. ;P
— David