anchor.diff:  
     postFixup = lib.optionalString qtClient ''
       wrapQtApp $out/bin/freeciv-qt
  +  '' + lib.optionalString gtkClient ''
  +    wrapGApp $out/bin/freeciv-gtk3.22
     '';
   
     enableParallelBuilding = true;
  
positive.code:     ++ lib.optional enableSqlite sqlite;
  
    dontWrapQtApps = true;
  
    configureFlags = [ "--enable-shared" ]
      ++ lib.optional sdlClient "--enable-client=sdl"
  
negative.code: { lib, stdenv, fetchFromGitHub, autoreconfHook, lua5_3, pkg-config, python3
  , zlib, bzip2, curl, xz, gettext, libiconv
  , sdlClient ? true, SDL, SDL_mixer, SDL_image, SDL_ttf, SDL_gfx, freetype, fluidsynth
  , gtkClient ? false, gtk3, wrapGAppsHook
  , qtClient ? false, qt5
  , server ? true, readline
  , enableSqlite ? true, sqlite
  