| A module cannot be found and therefore, the visibility cannot be determined. | |
| Erroneous code example: | |
| ```compile_fail,E0578,edition2018 | |
| foo!(); | |
| pub (in ::Sea) struct Shark; // error! | |
| fn main() {} | |
| ``` | |
| Because of the call to the `foo` macro, the compiler guesses that the missing | |
| module could be inside it and fails because the macro definition cannot be | |
| found. | |
| To fix this error, please be sure that the module is in scope: | |
| ```edition2018 | |
| pub mod Sea { | |
| pub (in crate::Sea) struct Shark; | |
| } | |
| fn main() {} | |
| ``` |