https://developers.weixin.qq.com/miniprogram/dev/component/scroll-view.html

1. 官方提供的scrollview列表构造器示例代码，只要页面的scroll-view 设置成 custom 模式，Mac 和Windows端自动预览就加载不出来，报错如下

SystemError (jsEnginScriptError)

Cannot read properties of undefined (reading 'item')

TypeError: Cannot read properties of undefined (reading 'item')

    at h (https://usr/chunk_2.appservice.js:1:962)

    at t.handleChildrenUpdate (https://usr/common.app.js:1:32623)

    at https://usr/common.app.js:1:32769

    at g (https://usr/chunk_2.appservice.js:1:1767)

    at t.handleChildrenUpdate (https://usr/common.app.js:1:32623)

    at https://usr/common.app.js:1:32769

    at a (https://usr/chunk_2.appservice.js:1:2890)

    at t.handleChildrenUpdate (https://usr/common.app.js:1:32623)

    at t.update (https://usr/common.app.js:1:30960)

    at https://usr/common.app.js:1:36367