sangria.execution.AttributeCoercionError: Error during attribute coercion. Violations:
Variable 'skus' is used in a place where it is not allowed to be used.
	at sangria.schema.Args$.convert(Context.scala:392)
	at sangria.schema.Args$.$anonfun$apply$4(Context.scala:370)
	at scala.Option.flatMap(Option.scala:271)
	at sangria.schema.Args$.$anonfun$apply$3(Context.scala:370)
	at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238)
	at scala.collection.immutable.Set$Set1.foreach(Set.scala:97)
	at scala.collection.TraversableLike.map(TraversableLike.scala:238)
	at scala.collection.TraversableLike.map$(TraversableLike.scala:231)
	at scala.collection.AbstractSet.scala$collection$SetLike$$super$map(Set.scala:51)
	at scala.collection.SetLike.map(SetLike.scala:104)
	at scala.collection.SetLike.map$(SetLike.scala:104)
	at scala.collection.AbstractSet.map(Set.scala:51)
	at sangria.schema.Args$.apply(Context.scala:368)
	at sangria.schema.Args$.apply(Context.scala:382)
	at sangria.execution.Resolver$$anonfun$sangria$execution$Resolver$$loop$1$1.$anonfun$applyOrElse$1(Resolver.scala:1168)

query bySkus($skus: [String!]) {
  products(skus: $skus) {
    results {
      masterData {
        current {
          allVariants(skus: $skus) {
            sku
          }
        }
      }
    }
  }
}