1 error: unsatisfied lifetime constraints
2 --> $DIR/issue-40510-1.rs:18:9
7 | |return type of closure is &'2 mut std::boxed::Box<()>
8 | lifetime `'1` represents this closure's body
10 | ^^^^^^ return requires that `'1` must outlive `'2`
12 = note: closure implements `FnMut`, so references to captured variables can't escape the closure
14 error: aborting due to previous error