One more thing: The GHC source distribution contains the Happy-generated parsers. This means that to build from a source tarball, Happy is not required. Unfortunately the configure script checks for it and aborts if it's not found. To counter the problem in the Gentoo ebuilds, I apply the attached patch to the source. I think it would be a good idea to incorporate this or something similar (ideally, configure should be able to detect the prebuilt-parsers and skip the check). Thanks for your time, Sven Moritz PS: The patch command should be patch -d /path/to/ghc-5.04/ -p 1 < without-happy-patch