## Compiler version 3.4.0 ## Minimized code ```scala //> using scala 3.4.0 //> using dep org.typelevel::kittens:3.2.0 import cats.kernel.Monoid import cats.derived.auto.monoid.given case class B(a: Option[Int]) case class A(b: Option[B]) val _ = Monoid[A].empty ``` ## Output ```scala [error] No given instance of type cats.derived.DerivedMonoid[scala$minus3$u002E4$minusbug$_.this.A] was found. ``` ## Expectation Compiles fine in 3.3.3