anchor.diff: -{ stdenv, fetchurl, libspotify, alsaLib, readline, pkgconfig, apiKey, unzip }:
  +{ stdenv, fetchurl, libspotify, alsaLib, readline, pkgconfig, apiKey, unzip, gnused }:
   
   let version = "12.1.51"; in
   
  -if (stdenv.system == "x86_64-linux" && stdenv.system != "x86_64-darwin")
  +if (stdenv.system != "x86_64-linux" && stdenv.system != "x86_64-darwin")
   then throw "Check https://developer.spotify.com/technologies/libspotify/ for a tarball for your system and add it here"
   else stdenv.mkDerivation {
     name = "libspotify-${version}";
  
positive.code:   # common
    buildPhase = "true";
    # no patch or build phase for darwin
    phases = [ "unpackPhase" "installPhase" ]
      ++ stdenv.lib.optionals (stdenv.system == "x86_64-linux")
        [ "patchPhase" "buildPhase" ];
    installPhase = if (stdenv.system == "x86_64-linux")
      then "installPhase"
      else ''
  
negative.code:   installFlags = stdenv.lib.optionalString (stdenv.system == "x86_64-linux")
      "prefix=$(out)";
    patchPhase = stdenv.lib.optionalString (stdenv.system == "x86_64-linux")
      "${gnused}/bin/sed -i 's/ldconfig//' Makefile";
    postInstall = stdenv.lib.optionalString (stdenv.system == "x86_64-linux")
      "mv -v share $out";
  
  