error[E0658]: `async` blocks are not allowed in constants
  --> $DIR/issue-78722-2.rs:15:20
   |
LL |         let f: F = async { 1 };
   |                    ^^^^^^^^^^^
   |
   = note: see issue #85368 <https://github.com/rust-lang/rust/issues/85368> for more information
   = help: add `#![feature(const_async_blocks)]` to the crate attributes to enable

error[E0271]: expected `{async block@$DIR/issue-78722-2.rs:13:13: 13:21}` to be a future that resolves to `u8`, but it resolves to `()`
  --> $DIR/issue-78722-2.rs:11:30
   |
LL |         fn concrete_use() -> F {
   |                              ^ expected `()`, found `u8`

error: item constrains opaque type that is not in its signature
  --> $DIR/issue-78722-2.rs:15:20
   |
LL |         let f: F = async { 1 };
   |                    ^^^^^^^^^^^
   |
   = note: this item must mention the opaque type in its signature in order to be able to register hidden types
note: this item must mention the opaque type in its signature in order to be able to register hidden types
  --> $DIR/issue-78722-2.rs:15:20
   |
LL |         let f: F = async { 1 };
   |                    ^^^^^^^^^^^

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0271, E0658.
For more information about an error, try `rustc --explain E0271`.