error: unstable feature `feat_moo` is used without being enabled.
  --> $DIR/unstable-feature-exact-symbol.rs:37:5
   |
LL |     Bar::moo();
   |     ^^^
   |
   = help: The feature can be enabled by marking the current item with `#[unstable_feature_bound(feat_moo)]`
note: required for `Bar` to implement `Moo`
  --> $DIR/unstable-feature-exact-symbol.rs:29:6
   |
LL | #[unstable_feature_bound(feat_moo)]
   | ----------------------------------- unsatisfied trait bound introduced here
LL | impl Moo for Bar {
   |      ^^^     ^^^

error: aborting due to 1 previous error