# Steps to fix the https://github.com/rust-lang/rust/issues/80658

- [ ] Move the error message:
- from:

        4 |     async_fn()
          |     ^^^^^^^^^^ expected u8, found opaque type

- to:

        4 |     async_fn()
          |     ^^^^^^^^^^ expected `u8`, found future

- [x] move the note message:
- from:

        note: while checking the return type of the `async fn`
         --> test.rs:2:28
          |
        2 |     async fn async_fn() -> u8 {  22 }
          |                            ^^ checked the `Output` of this `async fn`, found opaque type
          = note:     expected type `u8`
                  found opaque type `impl Future<Output = u8>`

- to:

        2 |     async fn async_fn() -> u8 {  22 }
          |     ----- calling an async function returns a future

- [ ] this is missing some love to get the function signature span from the function call, [here](https://rust-lang.zulipchat.com/#narrow/stream/147480-t-compiler.2Fwg-diagnostics/topic/how.20to.20get.20the.20span.20of.20the.20function.20declaration) a possible discussion to solve the problem