error: unused pinned boxed `Future` trait object that must be used --> tests/ui/must_use.rs:9:5 | 9 | apples(3); | ^^^^^^^^^ | = note: futures do nothing unless you `.await` or poll them note: the lint level is defined here --> tests/ui/must_use.rs:1:9 | 1 | #![deny(unused_must_use)] | ^^^^^^^^^^^^^^^ error: unused return value of `apples` that must be used --> tests/ui/must_use.rs:9:5 | 9 | apples(3); | ^^^^^^^^^ | help: use `let _ = ...` to ignore the resulting value | 9 | let _ = apples(3); | +++++++