Recently I noticed that when I save a source file from my editor while having an IEx session running, the latter automatically recompiles my project. I’m pretty sure this never happened before, even though an LLM states this behavior has been going on since Elixir 1.15. Previously I’d use either an explicit recompile call in IEx, or just ran an HTTP request against an app endpoint which also did trigger recompilation.
This behavior is pretty confusing, since I’m not really sure when and why it started (although it did just some days ago), and I haven’t found a way to disable it. I’m aware about the IEx’s auto_reload feature which is disabled in my setup and is about reloading, and not recompilation anyway.
I’d like my IEx state to be unaffected by whatever intermediary edits I happen to do in the code until I decide to apply those explicitly. Please let me know what I’m missing.
We don’t autoreload automatically, unless you opt-in via auto_reload (as you mentioned) or unless you are using iex -S mix phx.server (as the Phoenix server autoreloads).
That’s what I was trying to highlight, but didn’t manage, sorry. I’m not asking about the auto_reload, which is, as you point out, opt-in anyway. It is about automatic recompilation. After I save a file in an editor, I see in my IEx:
Compiling 1 file (.ex)
Generated myapp app
I’d like to disable that behavior. When I’m ready to recompile, I’d prefer to explicitly do recompile() in IEx or send a browser request, this is the way it’s been for me for a long time.
Are you using Phoenix? Once again, we don’t do it by default. But if you are using Phoenix and the browser is open, auto reload will kick in and reload the page, leading to recompilations, and it has worked like this forever. 
I really need to bring my question asking together. Sorry for not giving enough information right away. Yes, I am using Phoenix, but only to serve API endpoints, there is no LiveView or anything. There is also no browser when this happens - its just IEx and an editor (either Cursor or a basic vim setup)…
Thank you for making me elaborate all this!
While I don’t have a browser, I recently added Prometheus and Grafana to my setup and they do generate frequent requests. So what I was taking for some unfamiliar IEx activity was just a regular recompilation during an incoming request.
Thanks again and sorry for all the noise 
3 Likes
No problem, glad you figured it out! 
1 Like
