how to overcome scala NoSuchMethodError?
<p>just getting started with scala and spark
trying to run this simple program:</p>

<pre><code>package spark.example

import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._
import org.apache.spark.SparkConf

object SparkGrep {
  def main(args: Array[String] = Array("default argument")) {
    val conf = new SparkConf().setAppName("SparkGrep").setMaster("localhost")
    val sc = new SparkContext(conf)
    val inputFile = sc.textFile("/Users/eugene/Downloads/hello.txt").cache()
    val matchTerm : String = "hello"
    val numMatches = inputFile.filter(line =&gt; line.contains(matchTerm)).count()
    println("%s lines in %s contain %s".format(numMatches, args(1), matchTerm))
    System.exit(0)
  }
}
</code></pre>

<p>Getting this error:</p>

<pre><code>Exception in thread "main" java.lang.NoSuchMethodError: scala.collection.immutable.HashSet$.empty()Lscala/collection/immutable/HashSet;
    at akka.actor.ActorCell$.&lt;init&gt;(ActorCell.scala:305)
    at akka.actor.ActorCell$.&lt;clinit&gt;(ActorCell.scala)
    at akka.actor.RootActorPath.$div(ActorPath.scala:152)
    at akka.actor.LocalActorRefProvider.&lt;init&gt;(ActorRefProvider.scala:465)
    at akka.remote.RemoteActorRefProvider.&lt;init&gt;(RemoteActorRefProvider.scala:124)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$2.apply(DynamicAccess.scala:78)
    at scala.util.Try$.apply(Try.scala:192)
    at akka.actor.ReflectiveDynamicAccess.createInstanceFor(DynamicAccess.scala:73)
    at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$3.apply(DynamicAccess.scala:84)
    at akka.actor.ReflectiveDynamicAccess$$anonfun$createInstanceFor$3.apply(DynamicAccess.scala:84)
    at scala.util.Success.flatMap(Try.scala:231)
    at akka.actor.ReflectiveDynamicAccess.createInstanceFor(DynamicAccess.scala:84)
    at akka.actor.ActorSystemImpl.&lt;init&gt;(ActorSystem.scala:550)
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:111)
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:104)
    at org.apache.spark.util.AkkaUtils$.createActorSystem(AkkaUtils.scala:96)
    at org.apache.spark.SparkEnv$.create(SparkEnv.scala:126)
    at org.apache.spark.SparkContext.&lt;init&gt;(SparkContext.scala:139)
    at spark.example.SparkGrep$.main(SparkGrep.scala:14)
    at spark.example.SparkGrep.main(SparkGrep.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
</code></pre>

<p>What should I change in this simple code to make it run?</p>