Error code E0429

The self keyword cannot appear alone as the last segment in a use declaration.

Erroneous code example:

use std::fmt::self; // error: `self` imports are only allowed within a { } list

To use a namespace itself in addition to some of its members, self may appear as part of a brace-enclosed list of imports:

use std::fmt::{self, Debug};

If you only want to import the namespace, do so directly:

use std::fmt;