# File lib/thor/base.rb, line 349
      def start(given_args=ARGV, config={})
        config[:shell] ||= Thor::Base.shell.new
        yield
      rescue Thor::Error => e
        if given_args.include?("--debug")
          raise e
        else
          config[:shell].error e.message
        end
        exit(1) if exit_on_failure?
      end