1 error[E0596]: cannot borrow `*x` as mutable, as `x` is not declared as mutable
2 --> $DIR/issue-36400.rs:5:7
5 | ^^^^^^^ cannot borrow as mutable
7 help: consider changing this to be mutable
9 LL | let mut x = Box::new(3);
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0596`.