ices/70877.rs: fixed with errors

=== stdout ===
=== stderr ===
error[E0271]: type mismatch resolving `<Bar as Iterator>::Item == Box<(dyn for<'r> Fn(&'r (dyn ToString + 'r)) -> Option<String> + 'static)>`
 --> /home/runner/work/glacier/glacier/ices/70877.rs:9:12
  |
6 | type FooRet = impl std::fmt::Debug;
  |               -------------------- the expected opaque type
...
9 | type Foo = impl Iterator<Item = FooItem>;
  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected opaque type, found enum `Option`
  |
  = note: expected struct `Box<(dyn for<'r> Fn(&'r (dyn ToString + 'r)) -> impl Debug + 'static)>`
             found struct `Box<(dyn for<'r> Fn(&'r (dyn ToString + 'r)) -> Option<String> + 'static)>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0271`.
==============

Author: rustbot