error[E0521]: borrowed data escapes outside of closure
  --> $DIR/regions-nested-fns.rs:12:9
   |
LL |     let mut ay = &y;
   |         ------ `ay` declared here, outside of the closure body
...
LL |     ignore::<Box<dyn for<'z> FnMut(&'z isize)>>(Box::new(|z| {
   |                                                           - `z` is a reference that is only valid in the closure body
...
LL |         ay = z;
   |         ^^^^^^ `z` escapes the closure body here

error[E0597]: `y` does not live long enough
  --> $DIR/regions-nested-fns.rs:5:18
   |
LL |     let y = 3;
   |         - binding `y` declared here
LL |     let mut ay = &y;
   |                  ^^ borrowed value does not live long enough
...
LL |         if false { return ay; }
   |                           -- returning this value requires that `y` is borrowed for `'static`
...
LL | }
   | - `y` dropped here while still borrowed

error[E0597]: `y` does not live long enough
  --> $DIR/regions-nested-fns.rs:10:15
   |
LL |     let y = 3;
   |         - binding `y` declared here
...
LL |     ignore::<Box<dyn for<'z> FnMut(&'z isize)>>(Box::new(|z| {
   |                                                          --- value captured here
LL |         ay = x;
LL |         ay = &y;
   |               ^ borrowed value does not live long enough
...
LL |         if false { return ay; }
   |                           -- returning this value requires that `y` is borrowed for `'static`
...
LL | }
   | - `y` dropped here while still borrowed

error: lifetime may not live long enough
  --> $DIR/regions-nested-fns.rs:17:27
   |
LL | fn nested<'x>(x: &'x isize) {
   |           -- lifetime `'x` defined here
...
LL |         if false { return x; }
   |                           ^ returning this value requires that `'x` must outlive `'static`

error: aborting due to 4 previous errors

Some errors have detailed explanations: E0521, E0597.
For more information about an error, try `rustc --explain E0521`.