> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# Debug mode

Rsbuild provides a debug mode to troubleshoot problems. Add the `DEBUG=rsbuild` environment variable when you run a build to enable it.

```bash
# Debug in development mode
DEBUG=rsbuild pnpm dev

# Debug in production mode
DEBUG=rsbuild pnpm build
```

In debug mode, Rsbuild prints additional log information and writes the Rsbuild and Rspack configs to the `dist` directory so you can inspect them.

## Log information

In debug mode, the terminal shows logs that start with `rsbuild`, including internal operations and the Rspack version in use.

```bash
$ DEBUG=rsbuild pnpm dev

  ...
  rsbuild 10:00:00 configuration loaded from: /path/to/...
  rsbuild 10:00:00 registering default plugins
  rsbuild 10:00:00 default plugins registered
  ...
```

Rsbuild also prints the following message to indicate that it has written the generated build configurations to disk. Open these files to review the contents.

```bash
config inspection completed, generated files:

   - Rsbuild config: /Project/demo/dist/.rsbuild/rsbuild.config.mjs
   - Rspack config (web): /Project/demo/dist/.rsbuild/rspack.config.web.mjs
```

## Rsbuild config file

In debug mode, Rsbuild automatically generates a `dist/.rsbuild/rsbuild.config.mjs` file that contains the final Rsbuild config after the framework finishes processing your settings.

The structure of the file is as follows:

```js title="rsbuild.config.mjs"
export default {
  dev: {
    // some configs...
  },
  source: {
    // some configs...
  },
  // other configs...
};
```

For a complete introduction to Rsbuild config, please see the [Configure Rsbuild](/guide/configuration/rsbuild.md) chapter.

## Rspack config file

Rsbuild also creates a `dist/.rsbuild/rspack.config.web.mjs` file with the final Rspack config that Rsbuild passes to Rspack.

The structure of the file is as follows:

```js title="rspack.config.web.mjs"
export default {
  resolve: {
    // some resolve configs...
  },
  module: {
    // some Rspack loaders...
  },
  plugins: [
    // some Rspack plugins...
  ],
  // other configs...
};
```

For a complete introduction to Rspack configs, please see [Rspack official documentation](https://rspack.rs/config/).