Wrong error raised when calling function with wrong arity

[josevalim]

Describe the bug

Take this code:

-module(foo).
-compile(export_all).

start() ->
  G = fun(X, Y) -> X + Y end,
  F = fun(A) -> G(A, 0) end,
  F(1, 2).

Then you run it:

$ erl -s foo
Erlang/OTP 26 [erts-14.0.2] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1] [jit]

Runtime terminating during boot ({{badfun,2},[{foo,-start/0-fun-1-,2,[{_},{_}]},{init,do_boot,3,[]}]})

Notice it failed with badfun, but it should have been badarity.

Affected versions

I have reproduced it on Erlang/OTP 26.0 and 27.0-rc2. I didn't check earlier versions (because I personally don't find it high priority :D).

Additional context

Originally reported here: elixir-lang/elixir#13447

Thank you. ❤️

[jhogberg]

Thanks for your report, I've fixed it in #8318 :-)