Rust エラー「cannot assign twice to immutable variable xxx」が発生した場合の対処法

fn main() {

    let n = 0;

    println!("{}", n);

    n = 1;

    println!("{}", n);

}

error[E0384]: cannot assign twice to immutable variable `n`
 --> sample.rs:7:5
  |
3 |     let n = 0;
  |         -
  |         |
  |         first assignment to `n`
  |         help: consider making this binding mutable: `mut n`
...
7 |     n = 1;
  |     ^^^^^ cannot assign twice to immutable variable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0384`.

fn main() {

    let mut n = 0;

    println!("{}", n);

    n = 1;

    println!("{}", n);

}