error: future cannot be sent between threads safely --> $DIR/issue-86507.rs:17:13 | LL | / Box::pin( LL | | async move { LL | | let x = x; LL | | } LL | | ) | |_____________^ future created by async block is not `Send` | note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync` --> $DIR/issue-86507.rs:19:29 | LL | let x = x; | ^ has type `&T` which is not `Send`, because `T` is not `Sync` = note: required for the cast from `Pin>` to `Pin + Send + 'async_trait)>>` help: consider further restricting this bound | LL | fn bar<'me, 'async_trait, T: Send + std::marker::Sync>(x: &'me T) | +++++++++++++++++++ error: aborting due to previous error