in src/torch_ucc_comm.cpp [258:264]
std::string ProcessGroupUCCLogger::getLogPrefix(torch_ucc_phase_t phase) {
// caller can override the phase stored locally
torch_ucc_phase_t phase_ =
(local_phase != phase && phase != TORCH_UCC_UNKNOWN) ? phase
: local_phase;
return c10::str(log_prefix, "[", ucc_phase_map.at(phase_), "]");
}