//@ edition:2018 //@ run-pass #![feature(must_not_suspend)] #![warn(must_not_suspend)] #[must_not_suspend = "You gotta use Umm's, ya know?"] struct Umm { _i: i64 } fn bar() -> Umm { Umm { _i: 1 } } async fn other() {} pub async fn uhoh() { let guard = bar(); //~ WARNING `Umm` held across other().await; drop(guard); } fn main() { }