npm 构建失败，类扩展值未定义不是构造函数或 null

Question

我已经查看了类似问题的其他答案，但我对 npm 不够熟悉，无法将它们转化为我所看到的内容。我正在尝试构建一个项目，但收到错误：

     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> (D:\Development\Website\prosystem88\node_modules\mini-css-extract-plugin\dist\CssDependency.js:12:46)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (D:\Development\Website\prosystem88\node_modules\mini-css-extract-plugin\dist\index.js:12:45)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)

....还有更多内容，但我认为这是唯一相关的部分，如果不是，请告诉我

index.js 区域：

     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> (D:\Development\Website\prosystem88\node_modules\mini-css-extract-plugin\dist\CssDependency.js:12:46)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (D:\Development\Website\prosystem88\node_modules\mini-css-extract-plugin\dist\index.js:12:45)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)

CSSDependency.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _webpack = _interopRequireDefault(require("webpack"));

var _webpackSources = _interopRequireDefault(require("webpack-sources"));

var _CssDependency = _interopRequireDefault(require("./CssDependency"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

我不断收到信息表明这可能是循环依赖，但我不明白在这种情况下这是怎么回事。任何指示都会有帮助。

我已经尝试了多种不同的小事情，但我对这个构建过程和 npm 还很迷茫，我担心我会把整个项目搞砸。

Answer 1

在这种情况下，问题是 mini-css-extract-plugin 需要 webpack >= 4.1.0

来源