error[E0503]: cannot use `y.1` because it was mutably borrowed --> $DIR/match-cfg-fake-edges2.rs:8:5 | LL | let r = &mut y.1; | -------- borrow of `y.1` occurs here ... LL | match y { | ^^^^^^^ use of borrowed `y.1` ... LL | r; | - borrow later used here error: aborting due to previous error For more information about this error, try `rustc --explain E0503`.