anchor.diff: -{stdenv, fetchurl, makeDesktopItem, copyDesktopItems, SDL, lua5_1, pkgconfig, SDL_mixer, SDL_image, SDL_ttf}:
  +{ lib, stdenv, fetchurl, makeDesktopItem, copyDesktopItems, SDL, lua5_1, pkg-config, SDL_mixer, SDL_image, SDL_ttf }:
  +
   stdenv.mkDerivation rec {
     pname = "fish-fillets-ng";
     version = "1.0.1";
  +
     src = fetchurl {
       url = "mirror://sourceforge/fillets/fillets-ng-${version}.tar.gz";
       sha256 = "1nljp75aqqb35qq3x7abhs2kp69vjcj0h1vxcpdyn2yn2nalv6ij";
  
positive.code:     comment     = "Puzzle game about witty fish saving the world sokoban-style";
      categories  = "Game;LogicGame;";
    }) ];
    postInstall=''
      # Install game data
      mkdir -p "$out/share/games/fillets-ng/"
      tar -xf ${data} -C "$out/share/games/fillets-ng/" --strip-components=1
      
      # Install game icon
      install -Dm644 ${./icon.xpm} $out/share/pixmaps/fish-fillets-ng.xpm
    '';
    meta = {
      inherit version;
      description = ''A puzzle game'';
      license = stdenv.lib.licenses.gpl2Plus;
      maintainers = [stdenv.lib.maintainers.raskin];
      platforms = stdenv.lib.platforms.linux;
      homepage = "http://fillets.sourceforge.net/";
    };
  }
  
negative.code:     url = "mirror://sourceforge/fillets/fillets-ng-data-${version}.tar.gz";
      sha256 = "169p0yqh2gxvhdilvjc2ld8aap7lv2nhkhkg4i1hlmgc6pxpkjgh";
    };
  
    nativeBuildInputs = [ pkg-config copyDesktopItems ];
    buildInputs = [ SDL lua5_1 SDL_mixer SDL_image SDL_ttf ];
  
    desktopItems = [ (makeDesktopItem {
      name = "fish-fillets-ng";
      exec = "fillets";
  