error[E0597]: `tmp0` does not live long enough --> $DIR/issue-52663-trait-object.rs:12:20 | LL | let tmp0 = 3; | ---- binding `tmp0` declared here LL | let tmp1 = &tmp0; | ^^^^^ borrowed value does not live long enough LL | Box::new(tmp1) as Box | ----------------------------------- borrow later captured here by trait object LL | }; | - `tmp0` dropped here while still borrowed error: aborting due to previous error For more information about this error, try `rustc --explain E0597`.