Circe Enumeratum knownDirectSubclasses compile time error

Error during compilation of a CirceEnum: knownDirectSubclasses observed before subclass registered

Using:

• Scala - 2.12.1
• enumeratum - 1.5.3
• enumeratum-circe - 1.5.3

Enumeratum ADT looks like:

import enumeratum._
sealed trait Role extends EnumEntry
case object Role extends CirceEnum[Role] with Enum[Role] {
  case object Service extends Role
  case object User extends Role
  val values = findValues
}

For this case, two errors are produced:

[error] knownDirectSubclasses of Role observed before subclass Service registered
[error] knownDirectSubclasses of Role observed before subclass User registered

[joan38]

Rename your Enum trait to AWhatwver. It just needs to start with a letter high enough in the alphabetical order. What a joke.

Using 2.12.2 See: https://github.com/circe/circe/issues/639

[zergin]

For other poor souls trying to get it to work. For me the fix was to force imports order:

import TextType._
import io.circe.generic.auto._
import de.heikoseeberger.akkahttpcirce.CirceSupport

where TextType extends EnumEntry. It does not matter weather enumerated types are used or not in the class (for me they’re not). The only thing that triggered working code path was to have all enumerated types imported before io.circe.generic.auto._.

This seems to work for both generic akka-http application and unit tests with isolated Circe encoding/decoding.