readManifest(dir, priorityRegistry, isRoot = false) {
    var _this4 = this;

    return this.getCache(`manifest-${dir}`, (0, (_asyncToGenerator2 || _load_asyncToGenerator()).default)(function* () {
      const manifest = yield _this4.maybeReadManifest(dir, priorityRegistry, isRoot);

      if (manifest) {
        return manifest;
      } else {
        throw new (_errors || _load_errors()).MessageError(_this4.reporter.lang('couldntFindPackagejson', dir), 'ENOENT');
      }
    }));
  }
Read normalized package info according yarn-metadata.json
throw an error if package.json was not found