anchor.diff:  
     preFixup = /* Ensure youtube-dl is available in $PATH for MPV */ ''
       wrapProgram $out/bin/mpv \
  -      --prefix PATH : "${pythonPackages.youtube-dl}/bin"
  +      --prefix PATH : "${python3Packages.youtube-dl}/bin"
     '';
   
     meta = with lib; {
  
positive.code: , openal
  , opengl-dummy
  , pulseaudio_lib
  , pythonPackages
  , rubberband
  , samba_client
  , sdl
  
negative.code:   nativeBuildInputs = [
      makeWrapper
      perl
      python3Packages.python
      python3Packages.docutils
      waf
      which
    ];
  