error[E0277]: `std::sync::MutexGuard<'_, ()>` cannot be sent between threads safely
  --> $DIR/issue-67893.rs:9:5
   |
LL | fn g(_: impl Send) {}
   |              ---- required by this bound in `g`
...
LL |     g(issue_67893::run())
   |     ^ `std::sync::MutexGuard<'_, ()>` cannot be sent between threads safely
   | 
  ::: $DIR/auxiliary/issue_67893.rs:7:20
   |
LL | pub async fn run() {
   |                    - within this `impl std::future::Future`
   |
   = help: within `impl std::future::Future`, the trait `std::marker::Send` is not implemented for `std::sync::MutexGuard<'_, ()>`
   = note: required because it appears within the type `for<'r, 's, 't0, 't1, 't2, 't3> {std::future::ResumeTy, std::sync::Arc<std::sync::Mutex<()>>, &'r std::sync::Mutex<()>, std::result::Result<std::sync::MutexGuard<'s, ()>, std::sync::PoisonError<std::sync::MutexGuard<'t0, ()>>>, &'t1 std::sync::MutexGuard<'t2, ()>, std::sync::MutexGuard<'t3, ()>, (), impl std::future::Future}`
   = note: required because it appears within the type `[static generator@issue_67893::run::{{closure}}#0 for<'r, 's, 't0, 't1, 't2, 't3> {std::future::ResumeTy, std::sync::Arc<std::sync::Mutex<()>>, &'r std::sync::Mutex<()>, std::result::Result<std::sync::MutexGuard<'s, ()>, std::sync::PoisonError<std::sync::MutexGuard<'t0, ()>>>, &'t1 std::sync::MutexGuard<'t2, ()>, std::sync::MutexGuard<'t3, ()>, (), impl std::future::Future}]`
   = note: required because it appears within the type `std::future::from_generator::GenFuture<[static generator@issue_67893::run::{{closure}}#0 for<'r, 's, 't0, 't1, 't2, 't3> {std::future::ResumeTy, std::sync::Arc<std::sync::Mutex<()>>, &'r std::sync::Mutex<()>, std::result::Result<std::sync::MutexGuard<'s, ()>, std::sync::PoisonError<std::sync::MutexGuard<'t0, ()>>>, &'t1 std::sync::MutexGuard<'t2, ()>, std::sync::MutexGuard<'t3, ()>, (), impl std::future::Future}]>`
   = note: required because it appears within the type `impl std::future::Future`
   = note: required because it appears within the type `impl std::future::Future`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.