error[E0716]: temporary value dropped while borrowed
  --> $DIR/issue-52049.rs:6:10
   |
LL |     foo(&unpromotable(5u32));
   |     -----^^^^^^^^^^^^^^^^^^-- temporary value is freed at the end of this statement
   |     |    |
   |     |    creates a temporary value which is freed while still in use
   |     argument requires that borrow lasts for `'static`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0716`.