Variable scoping issue with funs

[berbiche]

Hi,

I discovered an issue related to variable scoping where variables inside of a lambda affect the external scope.

A reproducible test case is the following:

-module(error).

-compile([export_all, nowarn_export_all]).

%% error.erl: The variable on line 17 at column 5 is expected to have type [T] but it has type #{any() => any()}
%%
%%        Variable =:= Variable
%%    end, []),
%%    Variable = lists:append(NotImportant, []),
%%    ^^^^^^^^
%%
-spec should_pass_variable_not_shadowed() -> list().
should_pass_variable_not_shadowed() ->
    NotImportant = lists:filter(fun(X) ->
        Variable = maps:from_list(X),
        Variable =:= Variable
    end, []),
    Variable = lists:append(NotImportant, []),
    Variable.