1error[E0499]: cannot borrow `v` as mutable more than once at a time
2  --> $DIR/one_line.rs:3:12
3   |
4LL |     v.push(v.pop().unwrap());
5   |     -------^^^^^^^----------
6   |     | |    |
7   |     | |    second mutable borrow occurs here
8   |     | first borrow later used by call
9   |     first mutable borrow occurs here
10
11error: aborting due to previous error
12
13For more information about this error, try `rustc --explain E0499`.
14