message: Added a urlFromPath so string matching of bundle filename actually matches (fixes shell merge).
diff: @@ -17,7 +17,7 @@ import File = require('vinyl');
  import {ProjectConfig} from 'polymer-project-config';
  import {Analyzer} from 'polymer-analyzer';
  import {Bundler, Options as BundlerOptions} from 'polymer-bundler';
  -import {generateShellMergeStrategy} from 'polymer-bundler/lib/bundle-manifest';
  +import {BundleStrategy, generateShellMergeStrategy} from 'polymer-bundler/lib/bundle-manifest';
  import {pathFromUrl, urlFromPath} from './path-transformers';
  import {BuildAnalyzer} from './analyzer';
  @@ -75,9 +75,13 @@ export class BuildBundler extends Transform {
  }
  async _buildBundles(): Promise<Map<string, string>> {
  - const strategy = this.config.shell ?
  - generateShellMergeStrategy(this.config.shell, 2) :
  - undefined;
  + let strategy: BundleStrategy;
  + const fragments = Array.from(this.config.allFragments);
  + if (this.config.shell) {
  + strategy = generateShellMergeStrategy(
  + urlFromPath(this.config.root, this.config.shell), 2);
  + fragments.push(this.config.shell);
  + }
  return this.bundler
  .bundle(
  this.config.allFragments.map(
  