static L<S> searchLocalMechListCopies_returnLines(S s) {
  if (empty(s)) null;
  new L<S> out;
  for (S listName : namesOfLocalMechListCopies()) pcall {
    for (S line : linesFromFile(remoteMechListMirrorFile(listName)))
      if (cic(line, s))
        out.add(line);
  }
  ret out;
}