lint-no-err.stderr

warning: cannot borrow `conflict` as mutable because it is also borrowed as immutable
  --> $DIR/lint-no-err.rs:20:5
   |
LL |     let prev = conflict.get();
   |                -------------- immutable borrow occurs here
LL |     conflict.insert(*prev + *x);
   |     ^^^^^^^^^^^^^^^^-----^^^^^^
   |     |               |
   |     |               immutable borrow later used here
   |     mutable borrow occurs here
   |
   = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
   = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
   = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>

warning: 1 warning emitted