error[E0277]: future cannot be sent between threads safely
  --> $DIR/nested-async-calls.rs:26:5
   |
LL | fn require_send<T: Send>(_val: T) {}
   |    ------------    ---- required by this bound in `require_send`
...
LL |     require_send(wrapped);
   |     ^^^^^^^^^^^^ future returned by `first` is not `Send`
   |
   = help: within `main::Wrapper<impl std::future::Future>`, the trait `std::marker::Send` is not implemented for `*const ()`
   = note: required because it appears within the type `third::{{closure}}#0::NotSend`
note: future is not `Send` as this value is used across an await
  --> $DIR/nested-async-calls.rs:17:5
   |
LL |     let _a: Outer;
   |         -- has type `third::{{closure}}#0::Outer`
LL |     dummy().await;
   |     ^^^^^^^^^^^^^ await occurs here, with `_a` maybe used later
LL | }
   | - `_a` is later dropped here
note: future is not `Send` as this value is used across an await
  --> $DIR/nested-async-calls.rs:8:5
   |
LL |     third().await;
   |     -------^^^^^^- `third()` is later dropped here
   |     |
   |     await occurs here, with `third()` maybe used later
   |     has type `impl std::future::Future`
note: future is not `Send` as this value is used across an await
  --> $DIR/nested-async-calls.rs:4:5
   |
LL |     second().await;
   |     --------^^^^^^- `second()` is later dropped here
   |     |
   |     await occurs here, with `second()` maybe used later
   |     has type `impl std::future::Future`
   = note: required because it appears within the type `impl std::future::Future`
   = note: required because it appears within the type `main::Wrapper<impl std::future::Future>`

error: aborting due to previous error

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