error[E0119]: conflicting implementations of trait `Database` for type `RootDatabase`
  --> $DIR/cycle-via-builtin-auto-trait-impl.rs:19:1
   |
LL | impl<T: RefUnwindSafe> Database for T {
   | ------------------------------------- first implementation here
...
LL | impl Database for RootDatabase {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `RootDatabase`

error: aborting due to 1 previous error

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