src/test/ui/generator/retain-resume-ref.stderr

   1 error[E0499]: cannot borrow `thing` as mutable more than once at a time
   2   --> $DIR/retain-resume-ref.rs:23:25
   3    |
   4 LL |     gen.as_mut().resume(&mut thing);
   5    |                         ---------- first mutable borrow occurs here
   6 LL |     gen.as_mut().resume(&mut thing);
   7    |                  ------ ^^^^^^^^^^ second mutable borrow occurs here
   8    |                  |
   9    |                  first borrow later used by call
  10
  11 error: aborting due to previous error
  12
  13 For more information about this error, try `rustc --explain E0499`.