error: lifetime may not live long enough
  --> ui/lockall_lifetime_reborrow.rs:20:35
   |
20 |         let _ = c.shared.lock(|s| &mut *s.a); // lifetime
   |                                -- ^^^^^^^^^ returning this value requires that `'1` must outlive `'2`
   |                                ||
   |                                |return type of closure is &'2 mut u32
   |                                has type `&'1 mut __rtic_internal_fooShared`