     [verbosity: verbosity,
      dev_mode: Keyword.get(overrides, :dev),
      erl_opts: Keyword.get(overrides, :erl),
-     no_tar:   Keyword.get(overrides, :no_tar, false)]
+     no_tar:   Keyword.get(overrides, :no_tar, false),
+     is_upgrade:   Keyword.get(overrides, :upgrade, false),
+     upgrade_from: Keyword.get(overrides, :upfrom, :latest)]
   end
 end


  defp parse_args(argv) do
    switches = [silent: :boolean, quiet: :boolean, verbose: :boolean,
                dev: :boolean, erl: :string, no_tar: :boolean]
    {overrides, _} = OptionParser.parse!(argv, switches)
    verbosity = :normal
    verbosity = cond do

               nil -> config
               o   -> %{config | :erl_opts => o}
             end
    config = %{config |
               :is_upgrade => Keyword.fetch!(opts, :is_upgrade),
               :upgrade_from => Keyword.fetch!(opts, :upgrade_from)}
    no_tar? = Keyword.get(opts, :no_tar)

    # build release
