error[E0119]: conflicting implementations of trait `PartialEq<Interval<_>>` for type `Interval<_>`
  --> $DIR/warn-when-cycle-is-error-in-coherence.rs:5:10
   |
LL |   #[derive(PartialEq, Default)]
   |            ^^^^^^^^^ conflicting implementation for `Interval<_>`
...
LL | / impl<T, Q> PartialEq<Q> for Interval<T>
LL | | where
LL | |     T: Borrow<Q>,
LL | |     Q: ?Sized + PartialOrd,
   | |___________________________- first implementation here
   |
   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 1 previous error

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