[4.0.0-beta.3] exiting webpack-dev-server process logs "99% end closing watch compilation" in terminal

Hello,

I have a webpack configuration using among other things:

• webpack v5.38
• html-webpack-plugin v5.3
• webpack-dev-server v4.0.0 (beta.3, but I also experienced it with beta.2)

The dev server works fine, including HMR. However whenever I exit the process (using ctrl+c), it logs a warning in the terminal (cannot figure out where it comes from, but my current thoughts points to this project, hope it is not my environment…)

• This is a bug
• This is a modification request

Code

// webpack.config.babel.js
// simplified extract: https://github.com/flo-sch/webpack-dev-server-issue-close-compilation/blob/master/webpack.config.babel.js

const coreConfiguration = {
  module: {
    rules: [
      {
        test: /\.[tj]sx?$/,
        use: [
          {
            loader: 'babel-loader'
          }
        ],
        exclude: /node_modules/
      }
      // ...
    ]
  },
  plugins: [
    // ...
    new HtmlWebpackPlugin({
      template: path.resolve(SRC_FOLDER, 'index.html'),
      path: BUILD_FOLDER,
      filename: 'index.html',
      // ...
    }),
  ],
  optimization: {
    splitChunks: {
      chunks: 'all'
    }
  },
  stats: {
    preset: 'normal',
    env: true,
    errorDetails: true
  }
};

const developmentConfiguration = merge(coreConfiguration, {
  mode: 'development',
  output: {
    clean: true,
    chunkFilename: '[name].chunk.js',
    crossOriginLoading: 'anonymous',
    filename: '[name].js',
    path: BUILD_FOLDER,
    publicPath: '/'
  },
  devtool: 'cheap-module-source-map',
  devServer: {
    // ...
    host: process.env.DEV_SERVER_HOST || 'localhost',
    port: process.env.DEV_SERVER_PORT || 1234,
    static: [
      {
        directory: BUILD_FOLDER,
        publicPath: '/',
        serveIndex: true,
        watch: true
      }
    ]
  },
  // ...
  optimization: {
    emitOnErrors: false,
    minimize: false,
    moduleIds: 'named'
  },
  performance: {
    hints: 'warning'
  }
});

const getWebpackConfiguration = (_env, args) => {
  const { mode } = args;

  switch (mode) {
    case 'development':
      return developmentConfiguration;
    case 'production':
      return productionConfiguration;
    default:
      throw new Error(`Unable to provide configuration for unknown environment: "${mode}"`);
  }
};

export default getWebpackConfiguration;

// package.json
{
  "scripts": {
    "dev": "cross-env BABEL_ENV=webpack NODE_ENV=development webpack serve --mode development --config webpack.config.babel.js --progress --open"
    // ...
  }
}

Please paste the results of webpack-cli info here, and mention other relevant information

➜ npx webpack-cli info

  System:
    OS: macOS 11.4
  Binaries:
    Node: 14.17.0 - ~/.nvm/versions/node/v14.17.0/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 6.14.13 - ~/.nvm/versions/node/v14.17.0/bin/npm
  Packages:
    compression-webpack-plugin: ^8.0.0 => 8.0.0 
    copy-webpack-plugin: ^9.0.0 => 9.0.0 
    csp-html-webpack-plugin: ^5.1.0 => 5.1.0 
    dotenv-webpack: ^7.0.0 => 7.0.3 
    html-webpack-plugin: ^5.3.1 => 5.3.1 
    image-minimizer-webpack-plugin: ^2.2.0 => 2.2.0 
    webpack: ^5.38.0 => 5.38.1 
    webpack-bundle-analyzer: ^4.4.0 => 4.4.2 
    webpack-cli: ^4.7.0 => 4.7.2 
    webpack-dev-server: ^4.0.0-alpha.3 => 4.0.0-beta.3 
    webpack-merge: ^5.8.0 => 5.8.0 
    webpack-subresource-integrity: ^5.0.0-alpha.5 => 5.0.0-alpha.5 
    workbox-webpack-plugin: ^6.1.0 => 6.1.5

Also perhaps worth mentioning that I use zsh?

➜ npx envinfo webpack

  System:
    OS: macOS 11.4
    Shell: 5.8 - /bin/zsh

Expected Behavior

Nothing happen after exiting webpack-dev-server process

Actual Behavior

A last message is shown in the terminal, stating:

99% end closing watch compilation

For Bugs; How can we reproduce the behavior?

Checkout the reproduction repository:

https://github.com/flo-sch/webpack-dev-server-issue-close-compilation

[alexander-akait]

I will look at this in near future

[alexander-akait]

Yep, it is duplicate https://github.com/webpack/webpack-dev-server/issues/1479, bug on webpack side, I priority this, hope we will fix it for stable v4 release