anchor.diff:  
       sourceRoot = ".";
   
  -  nativeBuildInputs = [ pkgconfig ];
  +    nativeBuildInputs = [ pkgconfig ];
       buildInputs = [ zlib libpng bzip2 SDL SDL_mixer unzip ];
   
       configurePhase = let
  
positive.code:   );
  
    ver1 = "120";
    ver2 = "2";
    ver3 = "2";
    version =   "${ver1}.${ver2}.${ver3}";
    ver_dash =  "${ver1}-${ver2}-${ver3}";
  
    binary_src = fetchurl {
      url = "mirror://sourceforge/simutrans/simutrans/${ver_dash}/simutrans-src-${ver_dash}.zip";
      sha256 = "1yi6rwbrnfd65qfz63cncw2n56pbypvg6cllwh71mgvs6x2c28kz";
    };
  
  
  
negative.code:       license = with licenses; [ artistic1 gpl1Plus ];
        maintainers = with maintainers; [ kkallio vcunat phile314 ];
        platforms = with platforms; linux; # TODO: ++ darwin;
      };
    };
  
  