编译没有报错，小程序报错了，怎么办找不到具体的错误的地方了。

[Vue warn]: Error in nextTick: "TypeError: Converting circular structure to JSON"
console.error @ VM1110:1
warn @ mp.runtime.esm.js:613
logError @ mp.runtime.esm.js:1883
globalHandleError @ mp.runtime.esm.js:1878
handleError @ mp.runtime.esm.js:1838
(anonymous) @ mp.runtime.esm.js:1977
flushCallbacks @ mp.runtime.esm.js:1904
Promise resolved (async)
timerFunc @ mp.runtime.esm.js:1930
nextTick @ mp.runtime.esm.js:1986
queueWatcher @ mp.runtime.esm.js:4284
update @ mp.runtime.esm.js:4426
notify @ mp.runtime.esm.js:730
reactiveSetter @ mp.runtime.esm.js:1055
proxySetter @ mp.runtime.esm.js:4513
cancelDate @ rattenking-dtpicker.vue:204
(anonymous) @ index.js:619
(anonymous) @ index.js:606
handleEvent @ index.js:596
r.safeCallback @ WAService.js:1
(anonymous) @ WAService.js:1
f @ WAService.js:1
(anonymous) @ WAService.js:1
(anonymous) @ WAService.js:1
e @ appservice?t=1555566530288:1859
r.registerCallback.t @ appservice?t=1555566530288:1859
l.forEach.t @ appservice?t=1555566530288:1859
(anonymous) @ appservice?t=1555566530288:1859
s.onmessage @ appservice?t=1555566530288:1859

<rui-date-picker class='input-1 flex1' fields="minute" :start="minDate" :end="end" :value="start" @change="timeChangeStart" @cancel="cancelSelect"></rui-date-picker>

onLoad() {
let now = new Date();
let d = formatTime(now, this.fmt);
this.minDate = d;
this.maxDate = formatTime(new Date(now.getFullYear() + 1, now.getMonth(), now.getDate(), now.getHours(), now.getMinutes(), now.getSeconds()), this.fmt);
this.start = d;
this.end = formatTime(new Date(now.getFullYear(), now.getMonth(), now.getDate(), 23, 59, 59), this.fmt);
}

timeChangeStart(time) {
this.start = time;
}