Julian Assange is currently living in the London Ecuadorian embassy to avoid being extradited to Sweden.
It's my understanding that diplomats are immune from prosecution, detention, and (presumably) extradition. While the host country can kick the diplomat out, I assume Assange would rather be in Ecuador than in the Ecuadorian embassy. Yet I've not seen any serious discussion of Ecuador naming him a diplomat or ambassador.
Is there some legal obstacle to naming an asylum-seeker a diplomat and thereby exfiltrating them from the host country? Does the Vienna Convention contemplate this loophole (or close it)?