{ stdenv, lib }: let inherit (lib) optional; in { debug }: args: let args_ = { qmakeFlags = (args.qmakeFlags or []) ++ optional (debug != null) (if debug then "CONFIG+=debug" else "CONFIG+=release"); cmakeFlags = (args.cmakeFlags or []) ++ [ "-DBUILD_TESTING=OFF" ] ++ optional (debug != null) (if debug then "-DCMAKE_BUILD_TYPE=Debug" else "-DCMAKE_BUILD_TYPE=Release"); enableParallelBuilding = args.enableParallelBuilding or true; }; in stdenv.mkDerivation (args // args_)