anchor.diff:          Match match = relativeImportRegExp.firstMatch(line);
           if (match != null) {
             Path relativePath = new Path(match.group(3));
  -          if (foundImports.contains(relativePath)) {
  +          if (foundImports.contains(relativePath.toString())) {
               continue;
             }
             if (relativePath.toString().contains('..')) {
  
positive.code:             print("relative paths containing .. are not allowed.");
              exit(1);
            }
            foundImports.add(relativePath);
            toSearch.add(libraryDir.join(relativePath));
          }
        }
  
negative.code:   assert(targetDir != null);
  
    // Copy all the relative imports of the multitest.
    Set<String> importsToCopy = _findAllRelativeImports(filePath);
    List<Future> futureCopies = [];
    for (String relativeImport in importsToCopy) {
      Path importPath = new Path(relativeImport);
      // Make sure the target directory exists.
      Path importDir = importPath.directoryPath;
      if (!importDir.isEmpty) {
  