You can debug webpack configuration using nodejs debug tool:

• Open terminal and run node --inspect-brk node_modules/webpack/bin/webpack.js.
• --inspect-brk will pause your app execution at line 1.
• You'll see a message like Debugger listening on ws://127.0.0.1:9229/0f2c936f-b1cd-4ac9-aab3-f63b0f33d55e.
• Now you have to attach the debugger.

Attach debugger in Chrome:

• Open Chrome browser.
• Type about:inspect in url bar and enter.
• Click on Open dedicated DevTools for Node.
• You may need to wait a bit before the debugger is attached.
• Now in the terminal you'll see a new message Debugger attached.
• App is paused at first line, click Resume script execution to run it and see the logs.

Attach debugger in VSCode:

• Open debug tab in VSCode.
• Click on open lunch.json.
• Click on "Add Configuration" button in the bottom left corner.
• Choose "nodejs:attach" configuration.
• You can also use debug menu or command palette to add the same settings as above.
• From debug tab select your configuration (Attach) and click the green play button.
• You may need to wait a bit before the debugger is attached.
• In the terminal you'll see a new message Debugger attached.
• App is paused at first line, click Continue to run it and see the logs.