I am making a module that has multi module file, 
and faced this problem when using role in different module.

For example we have two module Foo and Bar, and there is a role in each module.

```
module Foo { 
    role foo is export {

    }  
}

module Bar { 
    import Foo; 

    role bar is export does foo {

    }
} 

import Foo;
import Bar;

sub f(foo \k) { }

f(bar.new);

```

I thought the code is fine, but rakudo said it think bar is not a foo and reject to compile.

What's wrong here ?