error[E0597]: borrowed value does not live long enough
  --> $DIR/borrowck-ref-into-rvalue.rs:18:5
   |
14 |         Some(ref m) => { //~ ERROR borrowed value does not live long enough
   |              ----- borrow occurs here
...
18 |     }
   |     ^ borrowed value dropped here while still borrowed
19 |     println!("{}", *msg);
20 | }
   | - borrowed value needs to live until here
   |
   = note: consider using a `let` binding to increase its lifetime

error: aborting due to previous error(s)