Function WarnOldSerialization

src/common/error_msg.h:76–85

}

inline void WarnOldSerialization() {
  // Display it once is enough. Otherwise this can be really verbose in distributed
  // environments.
  static thread_local bool logged{false};
  if (logged) {
    return;
  }
  LOG(WARNING) << OldSerialization();
  logged = true;
}

[[nodiscard]] std::string InvalidModel(StringView fname);