[@vue/compiler-sfc] ::v-deep usage as a combinator has been deprecated. Use :deep(<inner-selector>) instead.

vue3打包提示下面错误：

[@vue/compiler-sfc] ::v-deep usage as a combinator has been deprecated. Use :deep(<inner-selector>) instead.

如下图：

原因是vue3使用sass预处理器使用::v-deep深度选择器而导致的：

<style scoped> ::v-deep .demo{background:yellow;}</style>

此种写法已经被抛弃，改成:deep即可：

<style scoped> :deep(.demo){background:yellow;}</style>