anchor.diff:      };
       gap4r8p8 = super.callPackage ./pkgs/applications/science/math/gap/4r8p8.nix {};
       # NOTE: gcc = super.gcc6;
  -    # TODO
  -    # haskell = super.haskell // {
  -    #   packages = super.haskell.packages // {
  -    #     ghc802 = super.haskell.packages.ghc802.override {
  -    #        overrides = self: super: {
  -    #          idris = self.dontHaddock self.idris;
  -    #          # FIXME: idris = self.callPackage ./pkgs/development/haskell-modules/idris {};
  -    #        };
  -    #      };
  -    #   };
  -    # };
       # imagemagick = super.imagemagick7;
       jdk = super.openjdk8;
       # FIXME
  
positive.code:   nixpkgs.config.allowUnfree = true;
    # nixpkgs.config.allowBroken = true; # HACK
  
    nixpkgs.config.packageOverrides = super: let self = super.pkgs; in {
      # camlp5 = super.ocamlPackages.camlp5_6_strict;
      # camlp5 = super.ocamlPackages.camlp5_6_transitional;
  
negative.code:   ]) ++ (with pkgs.haskellPackages; [
      # FIXME: Agda
      # FIXME: cabal2nix # NOTE: conflict with pandoc (and hpack and idris)
      ghc
      hpack
      idris
      # intero
  