I just spent some time chasing down a bug that would have been easier to find if I had seen a certain crash report - but it seems like crash reports are not being shown in Elixir by default?

For example, when a process started with proc_lib:spawn crashes in Erlang, a crash report is printed:

$ erl
Erlang/OTP 21 [erts-10.0] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]

Eshell V10.0  (abort with ^G)
1> proc_lib:spawn(fun() -> error(pang) end).
<0.78.0>
2> =CRASH REPORT==== 14-May-2019::10:00:59.621479 ===
  crasher:
    initial call: erl_eval:'-expr/5-fun-3-'/0
    pid: <0.78.0>
    registered_name: []
    exception error: pang
      in function  shell:apply_fun/3 (shell.erl, line 907)
    ancestors: [<0.76.0>]
    message_queue_len: 0
    messages: []
    links: []
    dictionary: []
    trap_exit: false
    status: running
    heap_size: 376
    stack_size: 27
    reductions: 207
  neighbours:

But not when doing the same thing in Elixir:

$ iex
Erlang/OTP 21 [erts-10.0] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe]

Interactive Elixir (1.7.3) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> :proc_lib.spawn(fn -> :erlang.error(:pang) end)
#PID<0.103.0>

(it’s better to use a plain spawn than proc_lib:spawn in code like this, but this is an easy way to provoke a crash report - and this is how the code I was debugging was written. With a plain spawn, we get an error report instead of a crash report, and it’s displayed clearly in both Erlang and Elixir.)

My questions:

• Why does this happen?
• Is this a bug or a feature? It seems to me like dropping error messages like this is incorrect, but perhaps I’m missing something.
• Should I change my Logger configuration somehow?