anchor.diff:      marble
       oxygen
       threadweaver
  -  ];
  +  ]
  +  ++ lib.optionals withJpeg2k [ jasper ];
   
     enableParallelBuilding = true;
   
  
positive.code: , exiv2
  , ffmpeg
  , flex
  , jasper
  , lcms2
  , lensfun
  , libgphoto2
  
negative.code:     exiv2
      ffmpeg
      flex
      lcms2
      lensfun
      libgphoto2
  