Vue项目，运行出现warning(Emitted value instead of an instance of Error)

组件：<XXXX v-for="item in items" />

warning：(Emitted value instead of an instance of Error) <XXXX v-for="item in items" />: component lists rendered with v-for should have explicit keys.

See https://vuejs.org/guide/list.html#key for more info.

解决方式：在组件中加入自定义的属性key值就好

<XXXX v-for="item in items" :key="item" />