Compiling umbrella siblings with and without optional dependencies leads to inconsistent apps

[tomekowal]

Existing issue

• I have searched existing issues and could not find a duplicate.

Elixir and Erlang/OTP versions

I got this while trying to update to Elixir 1.20

[os_mon] cpu supervisor port (cpu_sup): Erlang has closed
[os_mon] memory supervisor port (memsup): Erlang has closed
common_deps/shared_telemetry
** (EXIT from #PID<0.95.0>) an exception was raised:
    ** (RuntimeError) found error while checking types for Tesla.Adapter.Finch.stream/3:

** (RuntimeError) expected Finch.Response to return struct metadata, but got none
The exception happened while checking this code:

defp stream(req, name, opts) do
  owner = :erlang.self()
  ref = :erlang.make_ref()

  fun = fn
    {:status, status}, _acc -> status
    {:headers, headers}, status -> :erlang.send(owner, {ref, {:status, status, headers}})
    {:data, data}, _acc -> :erlang.send(owner, {ref, {:data, data}})
    {:trailers, trailers}, _acc -> trailers
    {:error, error}, _acc -> :erlang.send(owner, {ref, {:error, error}})
    {:error, error, _}, _acc -> :erlang.send(owner, {ref, {:error, error}})
  end

  task =
    Task.async(fn ->
      handle_stream_response(Finch.stream(req, name, nil, fun, opts), ref, owner)
    end)

  receive do
    {^ref, {:status, status, headers}} ->
      body =
        Stream.unfold(nil, fn _ ->
          receive do
            {^ref, {:data, data}} ->
              {data, nil}

            {^ref, :eof} ->
              Task.await(task)
              nil

            {^ref, {:error, _error}} ->
              Task.shutdown(task, :brutal_kill)
              nil
          after
            opts[:receive_timeout] ->
              Task.shutdown(task, :brutal_kill)
              nil
          end
        end)

      {:ok, %Finch.Response{trailers: [], status: status, headers: headers, body: body}}

    {^ref, {:error, error}} ->
      Task.shutdown(task, :brutal_kill)
      {:error, error}
  after
    opts[:receive_timeout] ->
      Task.shutdown(task, :brutal_kill)
      {:error, :timeout}
  end
end

Please report this bug at: [https://github.com/elixir-lang/elixir/issues](https://github.com/elixir-lang/elixir/issues?q=sort%3Aupdated-desc+is%3Aissue+state%3Aopen+)

        (elixir 1.20.0) lib/module/types/of.ex:473: Module.Types.Of.struct_instance/7
        (elixir 1.20.0) lib/module/types/expr.ex:747: Module.Types.Expr.of_tuple/7
        (elixir 1.20.0) lib/module/types/expr.ex:972: anonymous fn/7 in Module.Types.Expr.of_clauses/7
        (elixir 1.20.0) lib/module/types/expr.ex:992: anonymous fn/8 in Module.Types.Expr.of_clauses_fun/7
        (elixir 1.20.0) lib/enum.ex:2622: Enum."-reduce/3-lists^foldl/2-0-"/3
        (elixir 1.20.0) lib/module/types/expr.ex:983: Module.Types.Expr.of_clauses_fun/7
        (elixir 1.20.0) lib/enum.ex:2622: Enum."-reduce/3-lists^foldl/2-0-"/3
        (elixir 1.20.0) lib/module/types/expr.ex:572: anonymous fn/5 in Module.Types.Expr.of_expr/5

Let me know if you need som kind of reproduction, but it seems the error message already produces one.

Operating system

Linux Ubuntu

Current behavior

It errors, explicitely asking to open a bug here.

Expected behavior

If it is a typing violation, it should be reported.

[josevalim]

I will need a way to reproduce it indeed, since it is struct related. :) Perhaps a Mix.install with the Tesla version is enough?

[tomekowal]

I asked Claude for minimal reproduction based on our CI job and it prepared a repo that reproduces the crash. It even provided mechanism in REAMDE.md, but I am not familiar enough with Elixir compiler internals to verify if the explanation makes sense.
Even if it doesn't, I hope it is still helpful :)

https://github.com/tomekowal/elixir-15445-repro

In general, the error shows up when compiling app one by one in umbrella project.

[josevalim]

Once you said umbrella, I immediately knew what it was, even without checking the repository. It is because one app in the umbrella depends on Finch, the other one does not, so Tesla is compiled in two different states. That's not good. We may need to fix it in Mix instead but I am not quite sure how.

[josevalim]

@tomekowal the best fix for now is to make sure all of your apps depend on Finch so Tesla builds are consistent.

In any case, thanks for the repro, it makes it much easier for me to test and fix it!!!

[tomekowal]

Thank you!