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:1:31
  |
1 | #![feature(unsized_fn_params, unsized_locals)]
  |                               ^^^^^^^^^^^^^^
  |
  = note: see issue #48055 <rust-lang/rust#48055> for more information
  = note: `#[warn(incomplete_features)]` on by default

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)`
  = note: all values captured by value by a closure must have a statically known size

error: aborting due to previous error; 1 warning emitted

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