warning: unknown lint: `must_not_suspend` --> $DIR/gated.rs:4:1 | LL | #![deny(must_not_suspend)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the `must_not_suspend` lint is unstable = note: see issue #83310 for more information = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date = note: `#[warn(unknown_lints)]` on by default warning: 1 warning emitted