When Tor can't download microdescriptors (legacy/trac#21969), maybe it should try authorities or fallbacks (legacy/trac#23863), before it runs out of microdesc retries (legacy/trac#24113). But even after Tor has the microdescs it needs, it sometimes doesn't start building circuits again. Instead, it is in state "waiting for circuit". For the log messages, see: https://trac.torproject.org/projects/tor/ticket/21969#comment:82