rust/tests/ui/feature-gates/feature-gate-with_negative_coherence.stderr

error[E0119]: conflicting implementations of trait `Foo` for type `&_`
  --> $DIR/feature-gate-with_negative_coherence.rs:5:1
   |
LL | impl<T: std::ops::DerefMut> Foo for T { }
   | ------------------------------------- first implementation here
LL |
LL | impl<T> Foo for &T { }
   | ^^^^^^^^^^^^^^^^^^ conflicting implementation for `&_`
   |
   = note: downstream crates may implement trait `std::ops::DerefMut` for type `&_`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0119`.