### Bug report My company (Canva) has an extremely large web app that we build with Webpack. When we turn on [experiments.lazyCompilation](https://webpack.js.org/configuration/experiments/#experimentslazycompilation) with `devServer.hot: true` during "initial" page load the dev server will sometimes crash with the following error: ``` Error: Cannot remove headers after they are sent to the client at ServerResponse.removeHeader (node:_http_outgoing:804:11) at removeResponseHeader (/<omitted>/node_modules/.pnpm/webpack-dev-middleware@7.4.2_webpack@5.99.9/node_modules/webpack-dev-middleware/dist/utils/compatibleAPI.js:131:7) at sendError (/<omitted>/node_modules/.pnpm/webpack-dev-middleware@7.4.2_webpack@5.99.9/node_modules/webpack-dev-middleware/dist/middleware.js:175:9) at errorHandler (/<omitted>/node_modules/.pnpm/webpack-dev-middleware@7.4.2_webpack@5.99.9/node_modules/webpack-dev-middleware/dist/middleware.js:218:11) at Volume.ReadStream.<anonymous> (/<omitted>/node_modules/.pnpm/webpack-dev-middleware@7.4.2_webpack@5.99.9/node_modules/webpack-dev-middleware/dist/middleware.js:662:9) at Volume.ReadStream.emit (node:events:518:28) at Volume.ReadStream.emit (node:domain:489:12) at onread (/<omitted>/node_modules/.pnpm/memfs@4.17.1/node_modules/memfs/src/volume.ts:2366:12) at Immediate.<anonymous> (/<omitted>/node_modules/.pnpm/memfs@4.17.1/node_modules/memfs/src/volume.ts:902:9) at processImmediate (node:internal/timers:483:21) { code: 'ERR_HTTP_HEADERS_SENT' } ``` ### Expected Behavior The dev server not to crash. Naively this can be by wrapping [this function call](https://github.com/webpack/webpack-dev-middleware/blob/cf58ccc029b7d10b9d7440bf340eccb434f8fdb1/src/middleware.js#L245-L247) in a `res.headersSent` check but I'm not sure whether that is logically correct. ### How Do We Reproduce? TBC ``` npx webpack-cli info System: OS: Linux 6.8 Ubuntu 22.04.5 LTS 22.04.5 LTS (Jammy Jellyfish) CPU: (16) x64 Intel(R) Xeon(R) Platinum 8375C CPU @ 2.90GHz Memory: 92.18 GB / 123.81 GB Binaries: Node: 20.19.4 - /usr/bin/node npm: 10.8.2 - /usr/bin/npm Packages: babel-loader: ^8.0.6 => 8.2.4 css-loader: ^5.2.4 => 5.2.6 ejs-loader: ^0.5.0 => 0.5.0 file-loader: ^5.0.2 => 5.0.2 html-webpack-plugin: ~5.5.0 => 5.5.3 loader-runner: ^4.1.0 => 4.2.0 loader-utils: 3.3.1 => 3.3.1 postcss-loader: ^5.2.0 => 5.2.0 raw-loader: ^4.0.0 => 4.0.2 svg-url-loader: ^3.0.3 => 3.0.3 svgo-loader: ^3.0.0 => 3.0.0 swc-loader: 0.2.6 => 0.2.6 terser-webpack-plugin: ^5.2.4 => 5.3.9 thread-loader: ^4.0.2 => 4.0.2 ts-loader: ^9.4.4 => 9.4.4 url-loader: ^4.1.1 => 4.1.1 webfontloader: ^1.6.28 => 1.6.28 webpack: 5.99.9 => 5.99.9 webpack-bundle-analyzer: 4.10.2 => 4.10.2 webpack-cli: ^5.1.4 => 5.1.4 webpack-dev-server: 5.2.2 => 5.2.2 webpackbar: ^5.0.0-3 => 5.0.0-3 ```