Gitit is a wiki backed by a git, darcs, or mercurial filestore.

As a workaround, my modus operandi right now is to use virthualenv and build everything in there. I understand cabal-dev provides similar functionality, but I haven't used it. I've never had dependency conflicts when I build something from hackage in a virthualenv, so if you're still interested in trying it you might want to give that a shot.

If you really want to install from source, try cabal-dev (worked for me, see my other comment) or virtualhenv.

However, your statement about Ruby, Python, Perl and Node is BS. Especially Ruby is very hairy to get up and running unless you are happy with old versions from your distro. Setting up the Haskell platform is not a lot more difficult than tinkering with rvm and bundler and whatnot to get Ruby up and running. Python is a little better because most useful libs are included in the "batteries" that ship with the interpreter. But try to use a bunch of libs and you enter virtualenv hell.

And whenever a new major change comes out, a new world of hurt begins. Ruby 1.9, Python 3 and Perl 6 transitions have been really painful.

If these languages work better, it's only because your distro package maintainers spend more time working on it.

It is probably something very simple but would be much easier to figure out in real time, e.g. on the #haskell irc channel which generally handles such difficulties promptly. E.g. does a look at `ghc-pkg list` and `ghc-pkg check` suggest that something was broken?

(By the way, the comparison with Ruby and Python and Perl and Node is not that great; cabal is as much, or more, like `make` than `gem`, managing compilation, linking etc.; one uses it all the time locally where distribution is not in question; it looks like that is the aspect that you are bumping into.)