{
  allowUnfree = true;
  allowBroken = false;
  pulseaudio = true;
  packageOverrides = pkgs: rec {
    rPackages = pkgs.rPackages.override {
      overrides = {
        png = pkgs.rPackages.png.overrideDerivation (old: { nativeBuildInputs = old.nativeBuildInputs ++ [ pkgs.libpng.dev ]; });
      };
    };
    toxvpn = pkgs.callPackage /home/clever/apps/nix-misc/toxvpn.nix {};