{
  allowUnfree = true;


  packageOverrides = super: let self = super.pkgs; in
  {
    myHaskellEnv = self.pkgs.haskell.packages.ghc802.ghcWithHoogle
                     (haskellPackages: with haskellPackages; [
                       happy
                       hasktags
                       stylish-haskell
                       present
                       hlint
                       structured-haskell-mode
                       hindent
                       ghc
                       ghc-mod
                     ]);

    rustNightlyNixRepo = pkgs.fetchFromGitHub {
         owner = "solson";
         repo = "rust-nightly-nix";
         rev = "9e09d579431940367c1f6de9463944eef66de1d4";
         sha256 = "03zkjnzd13142yla52aqmgbbnmws7q8kn1l5nqaly22j31f125xy";
    };
    rustPackages = self.pkgs.callPackage rustNightlyNixRepo { };
  };
}