scallop #137 bug

build.sbt

scalaVersion := "2.11.0"

libraryDependencies += "org.rogach" %% "scallop" % "3.1.2"

Test.scala

import org.rogach.scallop._
import java.io.{Serializable, ByteArrayOutputStream, ByteArrayInputStream, ObjectOutputStream, ObjectInputStream}

trait PropsArgument extends ScallopConf {
  @transient val p: Map[String, String] = props[String]('D')
}

class TestConf(args: List[String]) extends ScallopConf(args) with Serialization with PropsArgument {
  val apples = opt[Int]("apples")
  verify()
}

class App(val conf: TestConf) extends Serializable {
  val overrideMap: Map[String, String] = conf.p
}

object Test {
  def main(args: Array[String]) {
    val conf = new TestConf(List("-a","3","-Dkey=value"))
    val app = new App(conf)

    val bos = new ByteArrayOutputStream()
    val out = new ObjectOutputStream(bos)
    out.writeObject(app)
    out.flush()
    out.close()

    val bytes = bos.toByteArray()

    val bis = new ByteArrayInputStream(bytes);
    val in = new ObjectInputStream(bis);

    val app2 = in.readObject().asInstanceOf[App]

    println(app2.conf.apples())
    println(app2.conf.p)
  }
}