打包报错 TypeError: Class extends value undefined is not a constructor or null

$ vue-cli-service build
 
⠋  Building for production... ERROR  TypeError: Class extends value undefined is not a constructor or null
TypeError: Class extends value undefined is not a constructor or null
    at Object.<anonymous> (/root/deploy/ui/node_modules/mini-css-extract-plugin/dist/CssDependency.js:12:46)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/root/deploy/ui/node_modules/mini-css-extract-plugin/dist/index.js:12:45)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
————————————————

先卸载 webpack

npm uninstall webpack

然后（直接带版本号安装4.1以上的就行了）：

npm install webpack -g // 全局安装
npm install webpack --save-dev // 项目内安装
或者
npm add webpack@latest --registry=https://registry.npm.taobao.org


其实只要 ： npm install mini-css-extract-plugin


就好了

https://blog.csdn.net/u013938484/article/details/106259913

只要 ： npm install mini-css-extract-plugin 就好了