Error code E0154

Imports (use statements) are not allowed after non-item statements, such as variable declarations and expression statements.

Here is an example that demonstrates the error:

fn f() {
    // Variable declaration before import
    let x = 0;
    use std::io::Read;
    // ...
}

The solution is to declare the imports at the top of the block, function, or file.

Here is the previous example again, with the correct order:

fn f() {
    use std::io::Read;
    let x = 0;
    // ...
}

See the Declaration Statements section of the reference for more information about what constitutes an item declaration and what does not.