error[E0658]: yield syntax is experimental
 --> tests/ui/yield_in_nested_fn.rs:6:13
  |
6 |             yield "hello";
  |             ^^^^^^^^^^^^^
  |
  = note: see issue #43122 <https://github.com/rust-lang/rust/issues/43122> for more information

error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
 --> tests/ui/yield_in_nested_fn.rs:6:13
  |
6 |             yield "hello";
  |             ^^^^^^^^^^^^^
  |
help: use `#[coroutine]` to make this closure a coroutine
  |
5 |         #[coroutine] fn foo() {
  |         ++++++++++++

error[E0627]: yield expression outside of coroutine literal
 --> tests/ui/yield_in_nested_fn.rs:6:13
  |
6 |             yield "hello";
  |             ^^^^^^^^^^^^^