config.nix

{
  allowUnfree = true;
  allowBroken = false;

  packageOverrides = pkgs: rec {
    haskellPackages = self: super: {
      mkDerivation = args: super.mkDerivation (args // {
        # enableLibraryProfiling = true;
      });
    };

    haskellEnv = ({ name, paths }:
      pkgs.buildEnv {
        inherit name;
        paths = [ (pkgs.haskellPackages.ghcWithHoogle paths) pkgs.graphviz ];
        ignoreCollisions = true;
      });

    haskellPkgs = haskellEnv {
      name = "haskellPkgs";
      paths = p: with p; [
        base containers bytestring bytestring-mmap
        text text-icu parsec parsers trifecta free
        comonad scotty mtl transformers binary cereal
        HFuse svg-tree X11 rasterific-svg
        pipes diagrams-rasterific pipes-concurrency
        cabal-install
      ];
    };
  };
}