shahryarjb
Hello. Based on a reporting bug (which was not bug
), @josevalim said I can not use Application.put_env inside compile time macro like this:
This makes it so Mix believes the build of your dependency stale because a compile env flag is changing.
quote do
[:validate_derive, :sanitize_derive]
|> Enum.each(fn item ->
if is_nil(Application.compile_env(:guarded_struct, item)) do
Application.put_env(:guarded_struct, item, Keyword.get(unquote(opts), item))
end
end)
But I have question. is there a way to put env in compile time and access it inside run-time?
Thank you in advance.
Refs:
- Add warning around runtime modification of compile env · elixir-lang/elixir@bd99dcc · GitHub
- Mix cannot build a macro library used in another library when macro is called more than once in project modules · Issue #13699 · elixir-lang/elixir · GitHub
- The dependency build is outdated error with getting lib from Github branch - #2 by shahryarjb
Trending in Questions
I having some trouble figuring out if I have set myself too strict of standards for my production server. Currently I can handle 75% of r...
New
Hello,
I’m trying to build a basic Phoenix web-app, and I’d like to use Tailwind.
However, when I launch mix phx.server, I get an error...
New
Hi everyone,
I am toying with the idea of building a “match maker” for giving personal help to people that wants to start coding.
I sta...
New
I’m working on a small exercise involving update_in/3, and I came up with this solution:
data = %{
name: "Periodic Table",
category:...
New
I’ve got trouble wrapping my head around the order in which functions are called in this snippet (from Phoenix’s authentication):
toke...
New
Is there any way to avoid the Hologram compiler running when using iex? It seems like the front-end code could potentially be disregarded...
New
** (ArgumentError) expected :max_attempts to be a positive integer, got: {:@, [line: 10, column: 19], [{:max_attempts, [line: 10, column:...
New
Other Trending Topics
Edit: 2026 May 15 - This post is archived.
Mob is alive!!
Main docs: mob v0.7.11 — Documentation
A bit of explanation for the slightly c...
New
I am happy to introduce the very α version of the new programming language compiled to BEAM.
Welcome Cure.
It has literally three kille...
New
Hobbes is a low-level distributed database for the Elixir programming language.
Hobbes provides a simple, safe, and scalable storage lay...
New
A little off-topic, but I feel like people here have a good head on their shoulders.
I used to be quite good at making software. Was luc...
New
Hey. Is there anyone here who creates agents in their apps? Not talking about using agents, but creating them. I’m finding it pretty diff...
New
ExRatatui lets you cook up rich terminal UIs in Elixir, powered by Rust’s ratatui via Rustler NIFs. Build interactive terminal applicatio...
New
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ai
- #ecto-query
- #elixirconf-us
- #blog-post
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #metaprogramming
- #hex










Showing Posts 1 to 5- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
LostKobrakai
I don’t think so, but even if there would I’d argue this is abusing the system. Config is an input to code compilation and running its result. It’s not an output of compiling code.
D4no0
Stop torturing poor elixir and make your own language already
.
shahryarjb
A healthy body, including hands, waist, and neck, needs proper nutrition in a normal country. Unfortunately, I don’t have any

al2o3cr
I haven’t entirely traced how that env is being used, but this one looks like you need a different approach for getting metadata to
ValidationDerive:https://github.com/mishka-group/mishka_developer_tools/blob/6364fbc54f4c84b8b087857f6e13b13c3d84a742/lib/macros/guarded_struct/derive/validation_derive.ex#L618
At an absolute minimum, you’d need to be able to distinguish “this module that said
guardedstructwants validation” from “this OTHER module that saidguardedstructdoesn’t want validation” - a single boolean in the application env isn’t sufficient for that.shahryarjb
Yes, I am trying to change my whole passing data to my
derivefunction. It needs lot of worksUpdate:
I left this option of my macro. it is not necessary, for now