Show notification only after server has actually started up.

[garyking]

The notification appears immediately when rerun gets ready to start the server, but the server hasn't actually started at that point. Show the notification when the server is actually running instead.

[alexch]

I think this is a vote for a --port option, where rerun will announce that some process is now listening on that port. On its own rerun can't tell if the server has really started since there's no way to know how long it takes between launching the process and being "actually" running.

[amree]

@alexch Sorry for bumping an old issue. I want to confirm whether this is still an issue as I'm having the same thought and just checking if there's a solution ready.