[Haskell-cafe] Cabal question

Hi there, I am busy making the Helium compiler available as a Cabal install. What I still need is a way to run some kind of postprocessing (like running a Makefile) after installation (as it happens this is for compiling the libraries that come with Helium). Does anyone know here whether that is supported and how, without having to resort to build-types like Make that for I actually want to avoid? best, Jur