error[E0277]: `::TNotSend` cannot be sent between threads safely --> tests/build_fail_checks/nosend.rs:19:5 | 19 | consume_send(don_not_send_me.unwrap()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `::TNotSend` cannot be sent between threads safely | = help: the trait `Send` is not implemented for `::TNotSend` note: required by a bound in `consume_send` --> tests/build_fail_checks/nosend.rs:24:42 | 24 | fn consume_send(_: impl Signal) {} | ^^^^ required by this bound in `consume_send` help: introduce a type parameter with a trait bound instead of using `impl Trait` | 13 | fn render_send(props: N) -> i32 where ::TNotSend: Send { | ++++++++++++++++++++++++++++++++++ ~ ++++++++++++++++++++++++++++++++++++++++++++++++