nixos-config/overlays/mumble/overlay.nix

{
  stdenv,
  lib,
  which,
  file,
  mumble,
  mumble_i686,
}: let
  binPath = lib.makeBinPath [which file];
in
  stdenv.mkDerivation {
    name = "mumble-overlay-${mumble.version}";

    inherit (mumble) src;

    phases = ["unpackPhase" "installPhase" "fixupPhase"];

    installPhase = ''
      mkdir -p $out/lib
      ln -s ${mumble}/lib/libmumble.so.1 $out/lib/

      ${
        lib.optionalString (mumble_i686 != null) ''
          mkdir -p $out/lib32
          ln -s ${mumble_i686}/lib/libmumble.so.1 $out/lib32/
        ''
      }

      install -Dm755 scripts/mumble-overlay $out/bin/mumble-overlay
      sed -i "s,/usr/lib,$out/lib,g" $out/bin/mumble-overlay
      sed -i '2iPATH="${binPath}:$PATH"' $out/bin/mumble-overlay
    '';

    meta = {
      platforms = lib.platforms.linux;
    };
  }