anchor.diff: -{stdenv, fetchurl, libgcrypt}:
  +{ stdenv, fetchurl, libgcrypt, yacc, flex }:
   
   # library that allows libbluray to play AACS protected bluray disks
   # libaacs does not infringe DRM's right or copyright. See the legal page of the website for more info.
  
positive.code: 
  
  let baseName = "libaacs";
      version  = "0.3.0";
  in
  
  stdenv.mkDerivation {
  
negative.code: 
    src = fetchurl {
      url = "http://download.videolan.org/pub/videolan/${baseName}/${version}/${baseName}-${version}.tar.bz2";
      sha256 = "155sah8z4vbp6j3sq9b17mcn6rj1938ijszz97m8pd2cgif58i2y";
    };
  
    buildInputs = [ libgcrypt ];
  
    nativeBuildInputs = [ yacc flex ];
  
    meta = with stdenv.lib; {
      homepage = http://www.videolan.org/developers/libbluray.html;
      description = "Library to access Blu-Ray disks for video playback";
      license = licenses.lgpl21;
      maintainers = with maintainers; [ abbradar ];
    };
  }
  