error[E0277]: the trait bound `(): ReturnsSend` is not satisfied
  --> $DIR/ice-issue-146191.rs:6:52
   |
LL | fn create_complex_future() -> impl Future<Output = impl ReturnsSend> {
   |                                                    ^^^^^^^^^^^^^^^^ the trait `ReturnsSend` is not implemented for `()`
   |
help: this trait has no implementations, consider adding one
  --> $DIR/ice-issue-146191.rs:13:1
   |
LL | trait ReturnsSend {}
   | ^^^^^^^^^^^^^^^^^
note: required by a bound in an opaque type
  --> $DIR/ice-issue-146191.rs:6:57
   |
LL | fn create_complex_future() -> impl Future<Output = impl ReturnsSend> {
   |                                                         ^^^^^^^^^^^

error[E0733]: recursion in an async block requires boxing
  --> $DIR/ice-issue-146191.rs:8:5
   |
LL |     async { create_complex_future().await }
   |     ^^^^^   ----------------------------- recursive call here
   |
   = note: a recursive `async fn` call must introduce indirection such as `Box::pin` to avoid an infinitely sized future

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0277, E0733.
For more information about an error, try `rustc --explain E0277`.