anchor.diff:    libs = {
       xpc = stdenv.mkDerivation {
         name   = "apple-lib-xpc";
  -      phases = [ "installPhase" "fixupPhase" ];
  +      dontUnpack = true;
   
         installPhase = ''
           mkdir -p $out/include
  
positive.code: 
      buildInputs = [ xar cpio python pbzx ];
  
      phases = [ "unpackPhase" "installPhase" "fixupPhase" ];
      outputs = [ "out" "dev" "man" ];
  
      unpackPhase = ''
  
negative.code:   framework = name: deps: stdenv.mkDerivation {
      name = "apple-framework-${name}";
  
      dontUnpack = true;
  
      # because we copy files from the system
      preferLocalBuild = true;
  