xhprof测试yii2项目，报告中返回“N;”

Question

用xhprof测试yii2项目，在xhprof_enable()函数跟xhprof_disable()函数之间利用httpclient请求接口，返回的报告里面只有“N;”导致报告展示页出错，其他任意没有用httpclient的地方报告返回正常，请问我该如何排查错误？

报告为“N;”的代码：

        xhprof_enable(XHPROF_FLAGS_NO_BUILTINS);
        $client = new Client();
        $response = $client->createRequest()
            ->setMethod('get')
            ->setUrl(\Yii::$app->params['api']['cms'] . '/nav/lists')
            ->setData($navdata)
            ->send();

        $xhprof_data = xhprof_disable();
        include_once "../utils/xhprof_lib.php";
        include_once "../utils/xhprof_runs.php";
        $xhprof_runs = new \XHProfRuns_Default();
        $run_id = $xhprof_runs->save_run($xhprof_data, 'dfadf');
        //xhprof_log中的结果为“N;”

报告正常代码：

        function add($a, $b){
            return $a + $b;
        }
        xhprof_enable(XHPROF_FLAGS_NO_BUILTINS);
        add(1, 3);
        $xhprof_data = xhprof_disable();
        include_once "../utils/xhprof_lib.php";
        include_once "../utils/xhprof_runs.php";
        $xhprof_runs = new \XHProfRuns_Default();
        $run_id = $xhprof_runs->save_run($xhprof_data, 'dfadf');
        //xhprof_log中的结果为“a:1:{s:6:"main()";a:2:{s:2:"ct";i:1;s:2:"wt";i:8;}}”