error: future cannot be sent between threads safely --> $DIR/issue-67252-unnamed-future.rs:21:11 | LL | spawn(async { | ___________^ LL | | let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send` LL | | AFuture.await; LL | | drop(a); LL | | }); | |_____^ future created by async block is not `Send` | = help: within `[async block@$DIR/issue-67252-unnamed-future.rs:21:11: 25:6]`, the trait `Send` is not implemented for `*mut ()` note: future is not `Send` as this value is used across an await --> $DIR/issue-67252-unnamed-future.rs:23:17 | LL | let a = std::ptr::null_mut::<()>(); // `*mut ()` is not `Send` | - has type `*mut ()` which is not `Send` LL | AFuture.await; | ^^^^^ await occurs here, with `a` maybe used later LL | drop(a); LL | }); | - `a` is later dropped here note: required by a bound in `spawn` --> $DIR/issue-67252-unnamed-future.rs:9:13 | LL | fn spawn(_: T) {} | ^^^^ required by this bound in `spawn` error: aborting due to previous error