# File lib/jekyll/watcher.rb, line 19
    def watch(options, site = nil)
      ENV["LISTEN_GEM_DEBUGGING"] ||= "1" if options['verbose']

      site ||= Jekyll::Site.new(options)
      listener = build_listener(site, options)
      listener.start

      Jekyll.logger.info "Auto-regeneration:", "enabled for '#{options["source"]}'"

      unless options['serving']
        trap("INT") do
          listener.stop
          puts "     Halting auto-regeneration."
          exit 0
        end

        sleep_forever
      end
    rescue ThreadError
      # You pressed Ctrl-C, oh my!
    end