error[E0597]: `tmp0` does not live long enough
  --> $DIR/issue-52663-trait-object.rs:12:20
   |
LL |         let tmp1 = &tmp0;
   |                    ^^^^^ borrowed value does not live long enough
LL |         box tmp1 as Box<Foo + '_>
   |         ------------------------- borrow later captured here by trait object
LL |     };
   |     - `tmp0` dropped here while still borrowed

error: aborting due to previous error

For more information about this error, try `rustc --explain E0597`.