[Nix-dev] patch: add haskell package for darcs version of cabal-install

[Corey O'Connor]

For this to work under GHC 7.4.1 I had to have this config:

        nixpkgs.config.packageOverrides = pkgs :
            {
                haskellPackages = pkgs.haskellPackages_ghc741;
                darcs = pkgs.haskellPackages_ghc6123.darcs;
            };

        environment.systemPackages =
               [ pkgs.haskellPackages.cabalInstall_darcs ];

-Corey O'Connor
coreyoconnor at gmail.com
http://corebotllc.com/