@NotNull
  private static DartLibInfo collectPackagesLibraryRoots(
      @NotNull final Project project, @NotNull final DartSdk sdk) {
    final DartLibInfo libInfo = new DartLibInfo(false);

    final Collection<VirtualFile> pubspecYamlFiles =
        FilenameIndex.getVirtualFilesByName(
            project, PUBSPEC_YAML, GlobalSearchScope.projectScope(project));
    final ProjectFileIndex fileIndex = ProjectRootManager.getInstance(project).getFileIndex();

    for (VirtualFile pubspecFile : pubspecYamlFiles) {
      final VirtualFile dotPackagesFile =
          pubspecFile.getParent().findChild(DotPackagesFileUtil.DOT_PACKAGES);
      final Module module =
          dotPackagesFile == null ? null : fileIndex.getModuleForFile(dotPackagesFile);

      if (dotPackagesFile != null
          && !dotPackagesFile.isDirectory()
          && module != null
          && DartSdkGlobalLibUtil.isDartSdkEnabled(module)) {
        final Map<String, String> packagesMap = DotPackagesFileUtil.getPackagesMap(dotPackagesFile);
        if (packagesMap != null) {
          for (Map.Entry<String, String> entry : packagesMap.entrySet()) {
            final String packageName = entry.getKey();
            final String packagePath = entry.getValue();
            if (isPathOutsideProjectContent(fileIndex, packagePath)) {
              libInfo.addPackage(packageName, packagePath);
            }
          }
        }
      }
    }

    return libInfo;
  }