[jhc] How to compile new libraries from Hackage?

so I'm feeling a bit lost and lonely outside the comforting embrace of cabal-install. I've read some of the discussions on this list, and I understand that it's not very practical to try to support Cabal as is, but what's the alternative method to compile libraries from Hackage? Where do the libraries go so jhc can find them? Is there a convention of some kind? cheers Mark