Compilation error: protocol Enumerable not implemented for nil of type Atom

[RKushnir]

Hi,

When trying to use the package, unfortunately, the compilation fails with the following error. It seems that Application.spec/2 somehow is returning nil. This is in a context of an umbrella app, if that matters.

could not compile dependency :my_app, "mix compile" failed.
You can recompile this dependency with "mix deps.compile my_app", update it with "mix deps.update my_app" or clean it with "mix deps.clean my_app"

** (Protocol.UndefinedError) protocol Enumerable not implemented for nil of type Atom
(elixir 1.12.3) lib/enum.ex:1: Enumerable.impl_for!/1
(elixir 1.12.3) lib/enum.ex:141: Enumerable.reduce/3
(elixir 1.12.3) lib/enum.ex:3958: Enum.flat_map/2
(mix_unused 0.4.0) lib/mix_unused/exports.ex:22: MixUnused.Exports.application/1
(mix_unused 0.4.0) lib/mix/tasks/compile.unused.ex:136: Mix.Tasks.Compile.Unused.after_compiler/5
(elixir 1.12.3) lib/enum.ex:2385: Enum."-reduce/3-lists^foldl/2-0-"/3
(mix 1.12.3) lib/mix/tasks/compile.all.ex:72: Mix.Tasks.Compile.All.compile/4
(mix 1.12.3) lib/mix/tasks/compile.all.ex:59: Mix.Tasks.Compile.All.with_logger_app/2

[RKushnir]

Could we check the return value of Application.load to see the error if the application fails to load?