webpack4构建失败

Question

按照http://mpvue.com/mpvue/#_3 构建mpvue项目，报错如下

unitls.js中function generateLoaders (loader, loaderOptions) {

// var ExtractTextPlugin = require('extract-text-webpack-plugin')
var MiniCssExtractPlugin = require('mini-css-extract-plugin')
function generateLoaders (loader, loaderOptions) {
    var loaders = [cssLoader, px2rpxLoader, postcssLoader]
    if (loader) {
      loaders.push({
        loader: loader + '-loader',
        options: Object.assign({}, loaderOptions, {
          sourceMap: options.sourceMap
        })
      })
    }

    // Extract CSS when that option is specified
    // (which is the case during production build)
    if (options.extract) {
      // return ExtractTextPlugin.extract({
      //   use: loaders,
      //   fallback: 'vue-style-loader'
      // })
      return [
        MiniCssExtractPlugin.loader,
        {
          loader: 'css-loader',
          options: {
            minimize: process.env.NODE_ENV === 'production'
          }
        }
      ]
    } else {
      return ['vue-style-loader'].concat(loaders)
    }

  }

ps: 依赖的模块都已经升级到最新版本，尝试把dev-sever.js中ompiler.plugin改为compiler.hooks.emit.tap，并没有解决问题