error: lifetime may not live long enough --> $DIR/unique-borrows-are-invariant-1.rs:6:31 | LL | fn extend_lifetime<'a, 'b>(x: &mut (&'a str,), y: &'b str) { | -- -- lifetime `'b` defined here | | | lifetime `'a` defined here LL | let mut closure = |input| x.0 = input; | ^^^^^^^^^^^ assignment requires that `'b` must outlive `'a` | = help: consider adding the following bound: `'b: 'a` error: aborting due to 1 previous error