Bar.rakumod

unit class Bar;
use Foo;

also does Foo;

Foo.rakumod

unit role Foo;

my role RA {
    method fails {
        say "But OK?";
    }
}

my class C does RA {
}

has $.obj = C.new;

method test {
    $!obj.fails;
}

role.raku

use lib $?FILE.IO.parent(1);
use Bar;

Bar.new.test;