ambiguous implicit resolution of Show.ContravariantShow[immutable.SortedMap[K, V]]

[chwthewke]

In the following code:

object ShowIssue {

  val ok = Show[SortedMap[Int, String]]
  val ko = implicitly[Show.ContravariantShow[SortedMap[Int, String]]]

}

the line val ko = ... fails to compile with:

ambiguous implicit values:
both method catsShowForMap in object Show of type [K, V](implicit evidence$9: cats.Show[K], evidence$10: cats.Show[V]): cats.Show[Map[K,V]]
and method catsShowForSortedMap in object Show of type [K, V](implicit evidence$12: cats.Show[K], evidence$13: cats.Show[V]): cats.Show[scala.collection.immutable.SortedMap[K,V]]
match expected type cats.Show.ContravariantShow[scala.collection.immutable.SortedMap[Int,String]]
val ko = implicitly[Show.ContravariantShow[SortedMap[Int, String]]]

This is rarely an issue in practice (just use the Show instance), except when a library attempts to specifically summon a ContravariantShow instance, such as kittens apparently does (since 3.1.0 I believe)

Seen with cats-core 2.10.0, under Scala 2.13.13

Thank you for your consideration

[chwthewke]

Oh, I was afraid to even look at how this might be fixable (because implicit priority problems are scaaary), but it seems it was easy and I made a PR #4575