ices/68543.rs: fixed with errors

=== stdout ===
=== stderr ===
warning: the feature `unsized_locals` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /home/runner/work/glacier/glacier/ices/68543.rs:1:12
  |
1 | #![feature(unsized_locals)]
  |            ^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default
  = note: see issue #48055 <rust-lang/rust#48055> for more information

error[E0277]: the size for values of type `(dyn Future<Output = T> + Unpin + 'static)` cannot be known at compilation time
 --> /home/runner/work/glacier/glacier/ices/68543.rs:6:17
  |
6 | async fn bug<T>(mut f: dyn Future<Output = T> + Unpin) -> T {
  |                 ^^^^^ doesn't have a size known at compile-time
  |
  = help: the trait `Sized` is not implemented for `(dyn Future<Output = T> + Unpin + 'static)`
  = help: unsized fn params are gated as an unstable feature
help: function arguments must have a statically known size, borrowed types always have a known size
  |
6 | async fn bug<T>(&mut f: dyn Future<Output = T> + Unpin) -> T {
  |                 ^

error: aborting due to previous error; 1 warning emitted

For more information about this error, try `rustc --explain E0277`.
==============