message: Bundle before unmapping the bundled files so that we can remap the bundled files afterwards.
diff: @@ -120,11 +120,12 @@ export class BuildBundler extends Transform {
  this._getFilesChangedSinceInitialAnalysis());
  const manifest = await this._generateBundleManifest();
  + const bundles = await this._bundler.bundle(manifest);
  // Remove the bundled files from the file map so they are not emitted later.
  this._unmapBundledFiles(manifest);
  - for (const [filename, document] of await this._bundler.bundle(manifest)) {
  + for (const [filename, document] of bundles) {
  this._mapFile(new File({
  path: pathFromUrl(this.config.root, filename),
  contents: new Buffer(parse5.serialize(document.ast)),
  