Function WarnEmptyDataset

src/common/error_msg.cc:53–57

}

void WarnEmptyDataset() {
  static std::once_flag flag;
  std::call_once(flag,
                 [] { LOG(WARNING) << "Empty dataset at worker: " << collective::GetRank(); });
}

void MismatchedDevices(Context const* booster, Context const* data) {
  static std::once_flag flag;