java.lang.NoSuchMethodError: scala.Predef$.refArrayOps

Question

I have the following class:

import scala.util.{Success, Failure, Try}   class MyClass {    def openFile(fileName: String): Try[String]  = {     Failure( new Exception("some message"))   }    def main(args: Array[String]): Unit = {     openFile(args.head)   }  } 

Which has the following unit test:

class MyClassTest extends org.scalatest.FunSuite {    test("pass inexistent file name") {     val myClass = new MyClass()     assert(myClass.openFile("./noFile").failed.get.getMessage == "Invalid file name")   }  } 

When I run sbt test I get the following error:

java.lang.NoSuchMethodError: scala.Predef$.refArrayOps([Ljava/lang/Object;)Lscala/collection/mutable/ArrayOps;         at org.scalatest.tools.FriendlyParamsTranslator$.translateArguments(FriendlyParamsTranslator.scala:174)         at org.scalatest.tools.Framework.runner(Framework.scala:918)         at sbt.Defaults$$anonfun$createTestRunners$1.apply(Defaults.scala:533)         at sbt.Defaults$$anonfun$createTestRunners$1.apply(Defaults.scala:527)         at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)         at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)         at scala.collection.immutable.Map$Map1.foreach(Map.scala:109)         at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)         at scala.collection.AbstractTraversable.map(Traversable.scala:105)         at sbt.Defaults$.createTestRunners(Defaults.scala:527)         at sbt.Defaults$.allTestGroupsTask(Defaults.scala:543)         at sbt.Defaults$$anonfun$testTasks$4.apply(Defaults.scala:410)         at sbt.Defaults$$anonfun$testTasks$4.apply(Defaults.scala:410)         at scala.Function8$$anonfun$tupled$1.apply(Function8.scala:35)         at scala.Function8$$anonfun$tupled$1.apply(Function8.scala:34)         at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)         at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)         at sbt.std.Transform$$anon$4.work(System.scala:63)         at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)         at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)         at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)         at sbt.Execute.work(Execute.scala:235)         at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)         at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)         at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)         at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)         at java.util.concurrent.FutureTask.run(FutureTask.java:266)         at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)         at java.util.concurrent.FutureTask.run(FutureTask.java:266)         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)         at java.lang.Thread.run(Thread.java:745) [error] (test:executeTests) java.lang.NoSuchMethodError: scala.Predef$.refArrayOps([Ljava/lang/Object;)Lscala/collection/mutable/ArrayOps; 

Build definitions:

version := "1.0"  scalaVersion := "2.12.0"  // https://mvnrepository.com/artifact/org.scalatest/scalatest_2.11 libraryDependencies += "org.scalatest" % "scalatest_2.11" % "3.0.0" 

I can't figure out what causes this. My class and unit test seem simple enough. Any ideas?

Answer 1

I had SDK in global libraries with a different version of Scala(IntelliJ IDEA).
File -> Project Structure -> Global libraries -> Remove SDK -> Rebuild. It fixed the Exception for me.