The `self` import appears more than once in the list.
Erroneous code example:
```compile_fail,E0430
use something::{self, self}; // error: `self` import can only appear once in
// the list
```
Please verify you didn't misspell the import name or remove the duplicated
`self` import. Example:
```
# mod something {}
# fn main() {
use something::{self}; // ok!
# }
```