未捕获的错误：找不到模块'./Sidebar/SideBar'Webpack Heroku

Question

尝试部署到heroku，但控制台出现错误： Main.js：4未捕获的错误：找不到模块“ ./Sidebar/SideBar” 在webpackMissingModule（Main.js：4）

./ Sidebar / SideBar是一个React组件。之前我已经将此应用程序部署到Heroku，没有问题。另外，通常在“部署”后，第一个负载可以工作，而第二个负载则不能。

webpack.config.js

const path = require('path');
const MinifyPlugin = require('babel-minify-webpack-plugin');
const CompressionPlugin = require('compression-webpack-plugin');

module.exports = {
  optimization: {
    minimizer: [new MinifyPlugin()],
  },
  entry: ['babel-polyfill', './client/index.js'],
  output: {
    path: __dirname,
    filename: './public/bundle.js',
  },
  mode: 'development',
  devtool: 'source-map',
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        include: [path.resolve(__dirname, 'client')],
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['env'],
          },
        },
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader'],
      },
      {
        test: /\.(png|jpe?g|gif)$/i,
        use: [
          {
            loader: 'file-loader',
          },
        ],
      },
    ],
  },
  plugins: [new CompressionPlugin()],
};

package.json

{
  "name": "slack-clone",
  "version": "1.0.0",
  "description": "A slack clone",
  "engines": {
    "node": "12.16.0"
  },
  "main": "index.js",
  "scripts": {
    "heroku-prebuild": "npm install --dev",
    "start": "npm run start-server & npm run build-watch",
    "start-server": "nodemon server -w server",
    "build-watch": "webpack -w",
    "deploy": "script/deploy",
    "production": "webpack -p",
    "seed": "node seed.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@material-ui/core": "^4.10.1",
    "@material-ui/icons": "^4.9.1",
    "axios": "^0.19.2",
    "bootstrap": "^3.4.1",
    "compression": "^1.7.4",
    "emoji-mart": "^3.0.0",
    "emoji-picker-react": "^3.2.1",
    "express": "^4.16.4",
    "moment": "^2.27.0",
    "morgan": "^1.9.1",
    "pg": "^6.1.2",
    "pg-hstore": "^2.3.2",
    "react": "^16.8.1",
    "react-dom": "^16.8.1",
    "react-expand-animated": "^1.0.2",
    "react-hook-form": "^5.7.2",
    "react-icons": "^3.10.0",
    "react-redux": "^7.2.0",
    "react-resizable": "^1.10.1",
    "react-resize-panel": "^0.3.5",
    "react-router-dom": "^4.3.1",
    "react-scroll": "^1.8.0",
    "react-scroll-to-bottom": "^3.0.0",
    "redux": "^4.0.5",
    "redux-thunk": "^2.3.0",
    "sequelize": "^5.15.1",
    "socket.io": "^1.7.2",
    "webpack": "^4.29.3",
    "webpack-cli": "^3.3.11"
  },
  "devDependencies": {
    "babel-core": "^6.26.3",
    "babel-loader": "^7.1.5",
    "babel-minify-webpack-plugin": "^0.3.1",
    "babel-polyfill": "^6.26.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-react": "^6.24.1",
    "babel-preset-stage-2": "^6.24.1",
    "compression-webpack-plugin": "^4.0.0",
    "css-loader": "^1.0.1",
    "file-loader": "^6.0.0",
    "nodemon": "^1.18.9",
    "optimize-css-assets-webpack-plugin": "^5.0.3",
    "style-loader": "^0.21.0",
    "uglifyjs-webpack-plugin": "^2.2.0"
  }
}