error[E0733]: recursion in an async fn requires boxing
  --> $DIR/post-mono-layout-cycle-2.rs:30:5
   |
LL | /     async fn iter<T>(&mut self, iterator: T)
LL | |
LL | |     where
LL | |         T: IntoIterator<Item = ()>,
   | |___________________________________^
LL |       {
LL |           Blah::iter(self, iterator).await
   |           -------------------------------- recursive call here
   |
   = note: a recursive `async fn` call must introduce indirection such as `Box::pin` to avoid an infinitely sized future

note: the above error was encountered while instantiating `fn Wrap::<()>::ice`
  --> $DIR/post-mono-layout-cycle-2.rs:56:9
   |
LL |         t.ice();
   |         ^^^^^^^

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0733`.