1 error[E0596]: cannot borrow data in a `&` reference as mutable
2 --> $DIR/dont-print-desugared-async.rs:5:20
4 LL | async fn async_fn(&ref mut s: &[i32]) {}
7 | |cannot borrow as mutable through `&` reference
8 | help: consider changing this to be a mutable reference: `&mut ref mut s`
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0596`.