# File lib/puma/jruby_restart.rb, line 44
    def self.daemon_start(dir, argv)
      ENV['PUMA_DAEMON_RESTART'] = Process.pid.to_s

      if k = ENV['PUMA_JRUBY_DAEMON_OPTS']
        ENV['JRUBY_OPTS'] = k
      end

      cmd = argv.first
      argv = ([:string] * argv.size).zip(argv).flatten
      argv << :string
      argv << nil

      chdir(dir)
      ret = fork
      return ret if ret != 0
      execlp(cmd, *argv)
      raise SystemCallError.new(FFI.errno)
    end