Help with Node externals and a plugin that uses a child compiler

[sdc395]

Hi

I'm attempting to rewrite the PinoWebpackPlugin so that it works with Rspack. The trouble I am experiencing is that the processed output of the Pino transports (that must be Node worker-compatible) is full of webpackMissingModule errors for the Node built-ins (such as os and path). The output of the project using the plugin is fine. The project's rspack.config.ts sets target: 'node' and externalsPresets: { node: true }, and it appears that the child compiler inherits those options.

The apply method of my plugin is below. What am I missing that will configure Rspack to properly apply the child compiler's "externals"?

Thanks in advance
Simon

Edit: @rspack/core@1.6.4 and @rspack/cli@1.6.4

apply(compiler: Compiler) {

    // eslint-disable-next-line @typescript-eslint/naming-convention
    const BannerPlugin = compiler.webpack.BannerPlugin;
    // eslint-disable-next-line @typescript-eslint/naming-convention
    const EntryPlugin = compiler.webpack.EntryPlugin;

    // Add the transport look-up header to all entries.
    new BannerPlugin({ entryOnly: true, raw: true, banner: this.makeOverridesHeader() }).apply(compiler);

    compiler.hooks.make.tapAsync(PLUGIN_NAME, (compilation, callback) => {

        const childCompiler = compilation.createChildCompiler(
            `${PLUGIN_NAME}ChildCompiler`,
            {
                library: {
                    type: 'commonjs2',
                },
                iife: false,
            }, [],
        );

        // Add the compatibility footer to all transports.
        new BannerPlugin({ footer: true, raw: true, banner: compatibilityFooter }).apply(childCompiler);

        for (const transport of this.transports) {

            const source = resolve(compiler.context, 'node_modules', transport.source);

            new EntryPlugin(compiler.context, source, {
                name: transport.name,
                filename: transport.output,
            }).apply(childCompiler);
        }

        childCompiler.runAsChild((err) => { callback(err); });
    });
}