pub fn announce_serving(bound: SocketAddr)Expand description
Announce the address a Serve statement bound, on stdout and at once: Serving on http://<bound>.
Every tier prints it from here, after the listener is bound and before the first request is read,
so whoever started the server (the full-stack dev server, a test, an orchestrator) learns the real
address, including the port the system chose for a requested port 0. It is flushed because a
server never returns: anything left in a buffer would never be seen.