Member nfd::RibManager::slFindAnn (const Name &name, const SlFindAnnCallback &cb) const: In current implementation, if an slAnnounce operation is in progress, slFindAnn does not wait for that operation to complete and its result reflects the prior RIB state.
Member nfd::RibManager::slRenew (const Name &name, uint64_t faceId, time::milliseconds maxLifetime, const SlAnnounceCallback &cb): In current implementation, if an slAnnounce operation is in progress to create a Route or replace a prefix announcement, slRenew could fail because Route does not exist in existing RIB, or overwrite the new prefix announcement with an old one.

NFD: Named Data Networking Forwarding Daemon 22.12 documentation