error[E0596]: cannot borrow `data` as mutable, as it is not declared as mutable
  --> $DIR/issue-61187.rs:6:5
   |
LL | async fn response(data: Vec<u8>) {
   |                   ---- help: consider changing this to be mutable: `mut data`
LL |     data.reverse();
   |     ^^^^ cannot borrow as mutable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0596`.