static L<DialogIO> talkToVMsRunningProgram(S progID) {
  new L<DialogIO> l;
  for (DialogIO io : talkToAllVMs()) pcall {
    bool close = true;
    try {
      S pID = io.ask("what is the main program id?");
      if (sameSnippetID(pID, progID)) {
        close = false;
        l.add(io);
      }
    } finally {
      if (close) io.close();
    }
  }
  ret l;
}