[Jtsummers]

A single process could wait forever if no message ever arrives, yes. But it's not a deadlock since deadlock requires at least two processes that are waiting on each other in some fashion.

And responding to your lower down comment: Yes, if a third party could send `msg` to either of these it'd break the deadlock. In my example (and the cases I've caused this myself) there was no other process around to do that. But this is where, with experience, you learn to design things better and also use `after` clauses in the receive expression. This will cause them to time out and do something. Which may be to terminate and let a supervisor restart the whole thing or some other behavior.