[jonnycat]

Good call - I think you're right about IEx trapping the exit. The confusing part is that it still logs out this message:

  ** (exit) exited in: Task.await(%Task{mfa: {:erlang, :apply, 2}, owner: #PID<0.954.0>, pid: #PID<0.964.0>, ref: #Reference<0.1455049351.208994307.4788>}, 1)
    ** (EXIT) time out
    (elixir 1.14.3) lib/task.ex:830: Task.await/2

[dasyatidprime]

Yeah, I agree that the way that comes out is really awkward. The first line there is reporting the context from in the Task module (because task.ex includes it explicitly in the exit call), and then the second is reporting a strerror-like translation of the :timeout reason, but the lines aren't clearly linked together that way and look more like chained events. All of the %Task{} stuff of course is just the inspection of the argument, but if your eye jumps to the “pid” part it can look like it's reporting that that's the exiting process even though it's not. And then the part where the first “exited” is written in past tense as though the exit happened, when in fact it's describing what the trap just caused to not actually fully happen, is probably the most confusing of all.