SDKVersion 1.9.0

brand iPhone

model iPhone 6s<iPhone8,1>

system iOS 11.2.1

version 6.6.1

目前还不知如何复现，小程序正常使用情况下，有机率发生如下错误:

exparserScriptError value[@https](/user/https): undefined is not an object (evaluating 'this.patchIndexes.length')     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:12569 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:293 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:7:920     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:6:8219 doUpdates     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:7112 applyProperties     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2835 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2913     [native code] forEach     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2886 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:18:31496 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:7:1043 _advancedCreate     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:7:2086 create     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2114 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2913     [native code] forEach     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:2886 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:18:31496 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:7:1043 _advancedCreate     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:7:2086 create     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:18:27023 L     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:18:16827 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:17:27826 value     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:19222 h     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:20624 f     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:19827     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:19:24321     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:4:24866     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:5:5015 emit     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:5:26854     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:5:12851     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:2:2174 x     https://servicewechat.com/wxb80108bc52854112/14/page-frame.html:1:72 global code

发生在内核程式库

a = function() {     function e(t, n) {         r(this, e), this.oldTree = t, this.patches = n, this.patchIndexes = Object.keys(this.patches).map(function(e) {             return Number(e)         })     }       return o(e, [{         key: "apply",         value: function(e) {             var t = this;             if (0 === this.patchIndexes.length) return e;             var n = (0, i.getDomIndex)(e, this.oldTree, this.patchIndexes);             return this.patchIndexes.forEach(function(e) {                 var r = n[e];                 if (r) {                     t.patches[e].forEach(function(e) {                         e.apply(r)                     })                 }             }), e         }     }]), e }();

看似不明原因，this.patchIndexes.length 之 this.patchIndexes 是 undefined

请问要如何避免这个错误，谢谢