anchor.diff:    };
   
   in
  -assert stdenv.lib.assertMsg (enableClient || enableServer)
  +assert lib.assertMsg (enableClient || enableServer)
     "mindustry: at least one of 'enableClient' and 'enableServer' must be true";
   stdenv.mkDerivation rec {
     inherit pname version unpackPhase patches;
  
positive.code:     rm Arc/backends/backend-sdl/libs/linux64/libsdl-arc*.so
    '' + cleanupMindustrySrc;
  
    buildInputs = [
      SDL2
      glew
      alsaLib
  
negative.code:     gradle_6
      makeWrapper
      jdk
    ] ++ lib.optionals enableClient [
      ant
      copyDesktopItems
    ];
  
    desktopItems = lib.optional enableClient desktopItem;
  
    buildPhase = with lib; ''
      export GRADLE_USER_HOME=$(mktemp -d)
  
      # point to offline repo
      sed -ie "s#mavenLocal()#mavenLocal(); maven { url '${deps}' }#g" Mindustry/build.gradle
      sed -ie "s#mavenCentral()#mavenCentral(); maven { url '${deps}' }#g" Arc/build.gradle
  