Here’s a (incomplete) comparison between elixir 1.9 and distillery.
+------------+----------------+
| elixir1.9 | 1.8+distillery |
+------------+----------------+
| start | foreground |
| start_iex | console |
| daemon | n/a |
| daemon_iex | start |
| remote | remote_console |
| stop | stop |
| pid | pid |
| n/a | ping |
| n/a | attach |
+------------+----------------+
So the reason that attach is removed is mainly because when people attach to a background beam, it’s easy to kill the beam by accident if they didn’t use ctrl-d to detach.
So the daemon_iex is same as distillery’s start, where you can attach to the beam with iex. If we use daemon, then we can only interact with the background beam by remote to it. Even if we use to_erl to attach to it, we are unable to interact with it since iex is not started.
I think it’s worth mention the difference in the doc. Because it’s kinda confusing on what daemon_iex is do, and I guess most people don’t know what run_erl or to_erl does, since we rarely use them directly.
