{
  packageOverrides = pkgs: {
    mpv = let mpv = pkgs.mpv.override { youtubeSupport = true; theoraSupport = true; }; in pkgs.stdenv.mkDerivation {
      name = "mpv-wrapper";
      src = mpv;
      unpackPhase = "true";
      buildInputs = [ pkgs.makeWrapper pkgs.rsync ];
      installPhase = ''
        mkdir -p $out
        rsync -a $src/ $out/
        chmod u+w $out/bin
        wrapProgram $out/bin/mpv \
          --set JACK_PROMISCUOUS_SERVER 1 \
          --run "umask 0"
      '';
    };
    jackmeter = let jackmeter = pkgs.jackmeter.override {}; in pkgs.stdenv.mkDerivation {
      name = "jackmeter-wrapper";
      src = jackmeter;
      unpackPhase = "true";
      buildInputs = [ pkgs.makeWrapper pkgs.rsync ];
      installPhase = ''
        mkdir -p $out
        rsync -a $src/ $out/
        chmod u+w $out/bin
        wrapProgram $out/bin/jack_meter \
          --set JACK_PROMISCUOUS_SERVER 1 \
          --run "umask 0"
      '';
    };
    myHaskellPackages = pkgs.recurseIntoAttrs (
      pkgs.haskellPackages.override {
        extension = self: super: let
          callPackage = pkgs.lib.callPackageWith self;
        in
          beuteltier = callPackage custom/beuteltier.nix { fetchgit = pkgs.fetchgit; };
          wombat = callPackage custom/wombat.nix { fetchgit = pkgs.fetchgit; };
          opossum = callPackage custom/opossum.nix { fetchgit = pkgs.fetchgit; };
          opossumWrapper = callPackage custom/opossum-wrapper.nix {
            stdenv = pkgs.stdenv;
            makeWrapper = pkgs.stdenv.makeWrapper;
          };
      }
    );
  };
}