error[E0626]: borrow may still be in use when generator yields
  --> $DIR/issue-48048.rs:19:9
   |
LL |         x.0({ //~ ERROR borrow may still be in use when generator yields
   |         ^^^
LL |             yield;
   |             ----- possible yield occurs here

error: aborting due to previous error

For more information about this error, try `rustc --explain E0626`.