let
  pkgs = import <nixpkgs> { };

  ghc = with pkgs.haskell.lib;
    pkgs.ghc.withPackages (pkgs:
      with pkgs;
      [
        (doJailbreak (markUnbroken
          (biohazard.overrideAttrs (_: { patches = [ ./biohazard.patch ]; }))))
      ]);
in pkgs.stdenv.mkDerivation {
  name = "xenomapper-hs";
  buildInputs = [ ghc ];
  src = ./.;
  buildPhase = ''
    ghc -O3 xenomapper.hs -o xenomapper
  '';
  installPhase = ''
    install -D xenomapper $out/bin/xenomapper
  '';
}