static O openQuestion() {
  ret openQuestion(null);
}

static O openQuestion(S msg) {
  {
    lock appendToFile_lock;
    if (nempty(msg))
      logQuoted("openQuestions.txt", "Msg: " + msg);
    logQuoted("openQuestions.txt", getStackTrace());
  }
  fail(or2(msg, "Open question"));
}