vue 报错The "from" argument must be of type string. Received undefined

vuecli 打包报错： [Vue warn]: Error in render: The "from" argument must be of type string. Received undefined

报错原因：resolve没有配置extensions（文件引入省略后缀名）

解决办法：

configureWebpack: {  ...  resolve: {    extensions: ['.js', 'css', 'scss', '.vue'],    ...  }
  ...}