anchor.diff:    postFixup = ''
       for lib in $out/lib/*.so* ; do
         if [[ -L "$lib" ]]; then
  -        patchelf --set-rpath "$(patchelf --print-rpath $lib):${makeLibraryPath propagatedBuildInputs}" "$lib"
  +        patchelf --set-rpath "$(patchelf --print-rpath $lib):${rpath}" "$lib"
         fi
       done
     '';
  
positive.code:   nativeBuildInputs = [ pkgconfig ]
      ++ optional stdenv.isLinux libcap;
  
    propagatedBuildInputs = [ libiconv ]
      ++ optionals x11Support [ libXext libICE libXrandr ]
      ++ optionals openglSupport [ libGL libGLU ]
      ++ optional alsaSupport alsaLib
      ++ optional pulseaudioSupport libpulseaudio
      ++ optional stdenv.isDarwin Cocoa;
  
    buildInputs = [ ]
      ++ optional (!stdenv.hostPlatform.isMinGW && alsaSupport) audiofile
  
negative.code: # SDL2 expression too
  
  with stdenv.lib;
  
  let
    extraPropagatedBuildInputs = [ ]
      ++ optionals x11Support [ libXext libICE libXrandr ]
      ++ optionals openglSupport [ libGL libGLU ]
      ++ optional alsaSupport alsaLib
      ++ optional pulseaudioSupport libpulseaudio
      ++ optional stdenv.isDarwin Cocoa;
    rpath = makeLibraryPath extraPropagatedBuildInputs;
  in
  
  stdenv.mkDerivation rec {
    pname = "SDL";
  