Both GHC and its installer don't run on current Debian Stable
Currently it's not possible to run GHC or its installer. It fails with:
ghc: error while loading shared libraries: libgmp.so.3: cannot open shared object file: No such file or directory
The problem is that the current Debian stable is Wheezy and it uses a newer version of libgmp.
Proposed solution: Recompile on a recent Debian stable (Wheezy).
Applies to x86_64 as well, most likely all architectures supported by Debian are affected.