为什么在Scala REPL中抛出异常？

import scala.concurrent._
import scala.concurrent.duration._
import scala.concurrent.ExecutionContext.Implicits.global

// This is okay
val futureInt = Future[Int] { 42 }
val v1 = Await.result(futureInt,1.second)

// This throw error: java.lang.NoClassDefFoundError: Could not initialize class $line8.$read$$iw$$iw$$iw$$iw$$iw$$iw$
val v2 = Await.result(Future[Int]{ 42 },1.second)

但是当我创建一个主类并执行相同的代码时,它工作正常：

import scala.concurrent._
import scala.concurrent.duration._
import scala.concurrent.ExecutionContext.Implicits.global

object Main {
  def main(args: Array[String]): Unit = {
    val futureInt = Future[Int] { 42 }
    val v1 = Await.result(futureInt,1.second)
    val v2 = Await.result(Future[Int] { 44 },1.second)
    println(s"v1=$v1,v2=$v2 ")
  }
}

Output:

v1=42,v2=44