1error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
2  --> $DIR/issue-37139.rs:12:18
3   |
4LL |             test(&mut x);
5   |                  ^^^^^^
6   |                  |
7   |                  cannot borrow as mutable
8   |                  help: try removing `&mut` here
9
10error: aborting due to previous error
11
12For more information about this error, try `rustc --explain E0596`.
13