# File src/ruby_supportlib/phusion_passenger/vendor/crash_watch/gdb_controller.rb, line 94
    def close
      if !closed?
        begin
          execute("detach", 5)
          execute("quit", 5) if !closed?
        rescue Errno::EPIPE
        end
        if !closed?
          @in.close
          @out.close
          Process.waitpid(@pid)
          @pid = nil
        end
      end
    end