Warnings from git dependency's mix.exs issued on every mix task execution

[michallepicki]

Elixir and Erlang/OTP versions

Erlang/OTP 26 [erts-14.1.1] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns]

Elixir 1.16.0-rc.0 (792d4cc) (compiled with Erlang/OTP 26)

Operating system

happens on both linux amd64 and macos arm64

Current behavior

Hi! This is not a big issue, but it's a small annoyance that I noticed when trying out the 1.16.0-rc.0

When a git dependency has code in its mix.exs file which causes warnings, these warnings are printed not only when this dependency is compiled, but also every next time any mix task is executed.

Repro: https://github.com/michallepicki/elixir-1-16-git-dep-mix-exs-warnings-repro

mix deps.get
mix deps.compile

mix compile

# or any other task:
mix help
mix test

# result in these warnings being printed again and again:

    warning: parentheses are required for function calls with no arguments, got: Mix.env
    │
  8 │      build_embedded: Mix.env == :prod,
    │                          ~
    │
    └─ /var/home/michal/ubu/hmmm/deps/plug_forwarded_peer/mix.exs:8:26: PlugForwardedPeer.Mixfile.project/0

    warning: parentheses are required for function calls with no arguments, got: Mix.env
    │
  9 │      start_permanent: Mix.env == :prod,
    │                           ~
    │
    └─ /var/home/michal/ubu/hmmm/deps/plug_forwarded_peer/mix.exs:9:27: PlugForwardedPeer.Mixfile.project/0

Expected behavior

The warnings coming from a dependency are only printed when this dependency is being compiled

[josevalim]

There isn't much we can do here. The mix.exs for git dependencies is loaded every time you boot and therefore any warning will be emitted. We could silence warnings by capturing all IO but, given it can have side-effects, I would like to postpone taking such actions for now. What I will do is to postpone this particular warning itself, so there is more time to migrate.

[michallepicki]

There isn't much we can do here. The mix.exs for git dependencies is loaded every time you boot and therefore any warning will be emitted. We could silence warnings by capturing all IO but, given it can have side-effects, I would like to postpone taking such actions for now.

Understandable, thank you for the explanation!

What I will do is to postpone this particular warning itself, so there is more time to migrate.

For me it's not a big problem so I would be also fine with having to update the dependency or forking it