Mix cannot build a macro library used in another library when macro is called more than once in project modules

[shahryarjb]

Elixir and Erlang/OTP versions

Erlang/OTP 27 [erts-15.0] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1]

Elixir 1.17.1 (compiled with Erlang/OTP 27)

Operating system

MacOS 14.3.1 Intel

Current behavior

Imagine you have a project named user_managment and you want to install a dependency and a has a dependency which is a macro

In real case:

Create a mix new project

mix new user_management --sup

Put this library in you user_management mix.exs file

{:mishka_installer, "~> 0.1.0-alpha.1"}

As you see mishka_installer has {:mishka_developer_tools, "~> 0.1.6"} dependency inside itself which is macro

- user_management
- |___ mishka_installer
-      |_____ mishka_developer_tools

Error I get

==> user_management
Unchecked dependencies for environment dev:
* mishka_installer (Hex package)
  the dependency build is outdated, please run "mix deps.compile"
** (Mix) Can't continue due to errors on dependencies

Expected behavior

As you can see I use my macro in 2 places

• https://github.com/mishka-group/mishka_installer/blob/master/lib/event/event.ex#L60-L86
• https://github.com/mishka-group/mishka_installer/blob/master/lib/installer/installer.ex#L73-L95

If I delete one of them, my compiling error is fixed. it does not allow me to use it more than once

It should be noted if I install mishka_developer_tools directly in my project for example: user_management I can use it inside Unlimited modules and has no problem.

I sent a post in the forum, but after a thorough review and uninstallation and activation and deactivation of each line of the project, I was sure that this could be a bug in Elixir itself, so I created an issue for this purpose

Link: https://elixirforum.com/t/the-dependency-build-is-outdated-error-with-getting-lib-from-github-branch/64599/2

[josevalim]

You are changing a compile_env flag at compile-time:

https://github.com/mishka-group/mishka_developer_tools/blob/6364fbc54f4c84b8b087857f6e13b13c3d84a742/lib/macros/guarded_struct/guarded_struct.ex#L1500

This makes it so Mix believes the build of your dependency stale because a compile env flag is changing.

[shahryarjb]

@josevalim Sorry to wasted your time and pinging you again 🥹. you have any suggestion for this part of app you linked me what should i use instead of.
And where you can address me to read more about these problem and maybe add some doc for it
Thank you in advance

[josevalim]

I have pushed some new docs in main already. I am not sure what could be used instead, I didn’t try to fully understand what the code does, I only looked for the root cause of the bug. :)