After installing ghc for linux using rpm with
--prefix=/usr/local,
the ghc scriipt incorrectly thinks the libraries etc
are in /usr:

#!/bin/sh
GHCBIN="/usr/lib/ghc-6.2.2/ghc-6.2.2";
TOPDIROPT="-B/usr/lib/ghc-6.2.2";
# Mini-driver for GHC
exec $GHCBIN $TOPDIROPT ${1+"$@"}

After editing, at least the compiler actually starts up :)