Base{Selector,Proactor}EventLoop each have a sock_connect() method, both of which unconditionally "try" to run base_events' _check_resolved_address() which is apparently meant to raise an exception when called with an unresolved IP hostname. (because on some OSes it cannot be done asynchronously? WTF?)

Anyhow, the current implementation prevents ANY address family other than IP (and UNIX, which is special cased) to raise the exception, no matter if it's resolved or not.

So please, call _ipaddr_info() for IP only.