error[E0275]: overflow evaluating the requirement `Inc<Inc<Inc<Inc<Inc<Inc<Inc<...>>>>>>>: Trait`
  --> $DIR/global-cache.rs:21:19
   |
LL |     impls_trait::<Four<Four<Four<Four<()>>>>>();
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "18"]` attribute to your crate (`global_cache`)
note: required for `Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<()>>>>>>>>>>>` to implement `Trait`
  --> $DIR/global-cache.rs:12:16
   |
LL | impl<T: Trait> Trait for Inc<T> {}
   |         -----  ^^^^^     ^^^^^^
   |         |
   |         unsatisfied trait bound introduced here
   = note: 5 redundant requirements hidden
   = note: required for `Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<Inc<()>>>>>>>>>>>>>>>>` to implement `Trait`
note: required by a bound in `impls_trait`
  --> $DIR/global-cache.rs:15:19
   |
LL | fn impls_trait<T: Trait>() {}
   |                   ^^^^^ required by this bound in `impls_trait`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0275`.