error: variable does not need to be mutable --> $DIR/capture-mut-ref.rs:9:9 | LL | let mut x = &mut 0; | ----^ | | | help: remove this `mut` | note: the lint level is defined here --> $DIR/capture-mut-ref.rs:6:9 | LL | #![deny(unused_mut)] | ^^^^^^^^^^ error: aborting due to 1 previous error