Something other than a module was found in visibility scope.
Erroneous code example:
```compile_fail,E0577,edition2018
pub struct Sea;
pub (in crate::Sea) struct Shark; // error!
fn main() {}
```
`Sea` is not a module, therefore it is invalid to use it in a visibility path.
To fix this error we need to ensure `Sea` is a module.
Please note that the visibility scope can only be applied on ancestors!
```edition2018
pub mod Sea {
pub (in crate::Sea) struct Shark; // ok!
}
fn main() {}
```