Dconf read-only DB for NixOS

gistfile1.txt

    # Create a read-only DB with default theme and font settings.
    programs.dconf.enable = true;
    programs.dconf.profiles.user =
    let
      customDconf = pkgs.writeTextFile {
        name = "nixos-user-dconf";
        destination = "/dconf/nixos-user-custom";
        text = ''
            [org/gnome/desktop/interface]
            cursor-theme='Numix-Cursor'
            font-name='Source Sans Pro 10'
        '';
      };

      customDconfDb = pkgs.stdenv.mkDerivation {
        name = "nixos-user-dconf-db";
        buildCommand = ''
          ${pkgs.gnome3.dconf}/bin/dconf compile $out ${customDconf}/dconf
        '';
      };
    in pkgs.stdenv.mkDerivation {
      name = "dconf-nixos-user-profile";
      buildCommand = ''
        # create a custom user profile
        echo -e "user-db:user\nfile-db:${customDconfDb}" > $out
      '';
    };