anchor.diff:      owner = "OpenOrienteering";
       repo = "mapper";
       rev = "v${version}";
  -    sha256 = "1fyhvf2y89hj7wj89kxccx3dqcja6ndy3w4rx1vmzrp246jpz7wb";
  +    sha256 = "1787f2agjzcyizk2m60icb44yv9dlwv6irw3k53fqfmwkhkd2h5p";
     };
   
     cmakeFlags =
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "OpenOrienteering-Mapper";
    version = "0.9.1";
  
    buildInputs = [ gdal qtbase qttools qtlocation qtimageformats
                    qtsensors clipper zlib proj doxygen cups];
  
negative.code:       OpenOrienteering Mapper is an orienteering mapmaking program
        and provides a free alternative to the existing proprietary solution.
      '';
      homepage = "https://www.openorienteering.org/apps/mapper/";
      license = licenses.gpl3;
      platforms = with platforms; linux ++ darwin;
      maintainers = with maintainers; [ mpickering sikmir ];
  