error[E0312]: lifetime of reference outlives lifetime of borrowed content... --> $DIR/issue-10291.rs:3:9 | LL | x | ^ | note: ...the reference is valid for the anonymous lifetime #2 defined on the body at 2:69... --> $DIR/issue-10291.rs:2:69 | LL | drop:: FnMut(&'z isize) -> &'z isize>>(Box::new(|z| { | _____________________________________________________________________^ LL | | x LL | | })); | |_____^ note: ...but the borrowed content is only valid for the lifetime `'x` as defined on the function body at 1:9 --> $DIR/issue-10291.rs:1:9 | LL | fn test<'x>(x: &'x isize) { | ^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0312`.