error: future cannot be sent between threads safely --> $DIR/issue-68112.rs:34:5 | LL | require_send(send_fut); | ^^^^^^^^^^^^ future created by async block is not `Send` | = help: the trait `Sync` is not implemented for `RefCell` note: future is not `Send` as it awaits another future which is not `Send` --> $DIR/issue-68112.rs:31:17 | LL | let _ = non_send_fut.await; | ^^^^^^^^^^^^ await occurs here on type `impl Future>>`, which is not `Send` note: required by a bound in `require_send` --> $DIR/issue-68112.rs:11:25 | LL | fn require_send(_: impl Send) {} | ^^^^ required by this bound in `require_send` error: future cannot be sent between threads safely --> $DIR/issue-68112.rs:43:5 | LL | require_send(send_fut); | ^^^^^^^^^^^^ future created by async block is not `Send` | = help: the trait `Sync` is not implemented for `RefCell` note: future is not `Send` as it awaits another future which is not `Send` --> $DIR/issue-68112.rs:40:17 | LL | let _ = make_non_send_future1().await; | ^^^^^^^^^^^^^^^^^^^^^^^ await occurs here on type `impl Future>>`, which is not `Send` note: required by a bound in `require_send` --> $DIR/issue-68112.rs:11:25 | LL | fn require_send(_: impl Send) {} | ^^^^ required by this bound in `require_send` error[E0277]: `RefCell` cannot be shared between threads safely --> $DIR/issue-68112.rs:60:5 | LL | require_send(send_fut); | ^^^^^^^^^^^^ `RefCell` cannot be shared between threads safely | = help: the trait `Sync` is not implemented for `RefCell` = note: required because of the requirements on the impl of `Send` for `Arc>` = note: required because it appears within the type `[static generator@$DIR/issue-68112.rs:47:31: 47:36]` = note: required because it appears within the type `from_generator::GenFuture<[static generator@$DIR/issue-68112.rs:47:31: 47:36]>` = note: required because it appears within the type `impl Future` = note: required because it appears within the type `impl Future>>` = note: required because it appears within the type `impl Future>>` = note: required because it appears within the type `{ResumeTy, impl Future>>, (), i32, Ready}` = note: required because it appears within the type `[static generator@$DIR/issue-68112.rs:55:26: 59:6]` = note: required because it appears within the type `from_generator::GenFuture<[static generator@$DIR/issue-68112.rs:55:26: 59:6]>` = note: required because it appears within the type `impl Future` note: required by a bound in `require_send` --> $DIR/issue-68112.rs:11:25 | LL | fn require_send(_: impl Send) {} | ^^^^ required by this bound in `require_send` error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0277`.