in build.sbt [11:18]
def scalaVersionSpecificFolders(srcBaseDir: java.io.File, scalaVersion: String): List[File] =
CrossVersion.partialVersion(scalaVersion) match {
case Some((2, y)) if y <= 12 =>
new java.io.File(s"${srcBaseDir.getPath}-2.12-") :: Nil
case Some((2, y)) if y >= 13 =>
new java.io.File(s"${srcBaseDir.getPath}-2.13+") :: Nil
case _ => Nil
}