Sbt unable to find List class definition on Scala 3.0.0-M2

Question

I have a scala project on SDK 16 using sbt on Intellij IDEA Ultimate. Here is my build.sbt file :

name := "meteo-france-client"

version := "0.1"

scalaVersion := "3.0.0-M2"

libraryDependencies += "org.scalatest" %% "scalatest" % "3.3.0-SNAP3" % Test

I have a test file src/scala/test/MainTest.scala with the following code :

import org.scalatest.funsuite.AnyFunSuite

class MainTest extends AnyFunSuite {
  test("Example") {
    assert(1 == 1)
  }
}

Please note that in the IDE, the word "scalatest" of the import statement as well as the "test" function name are shown as red and told to be not found, even if I can compile the project. While I'm able to compile, I cannot run the test. Actually, when I run the sbt test it gives me the following error :

[info] compiling 1 Scala source to C:\Users\adrie\OneDrive\Documents\dev\meteo-france-client\target\scala-3.0.0-M2\test-classes ...
[error] ## Exception when compiling 1 sources to C:\Users\adrie\OneDrive\Documents\dev\meteo-france-client\target\scala-3.0.0-M2\test-classes
[error] java.lang.NoClassDefFoundError: scala/collection/immutable/List
[error] xsbt.CachedCompilerImpl.run(CachedCompilerImpl.java:65)
[error] xsbt.CompilerInterface.run(CompilerInterface.java:41)
[error] java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error] java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
[error] java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error] java.base/java.lang.reflect.Method.invoke(Method.java:567)
[error] sbt.internal.inc.AnalyzingCompiler.invoke(AnalyzingCompiler.scala:329)
[error] sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:112)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$7(MixedAnalyzingCompiler.scala:192)
[error] scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
[error] sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:247)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:182)
[error] sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4$adapted(MixedAnalyzingCompiler.scala:163)
[error] sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:239)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:163)
[error] sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:210)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5(Incremental.scala:175)
[error] sbt.internal.inc.Incremental$.$anonfun$apply$5$adapted(Incremental.scala:173)
[error] sbt.internal.inc.Incremental$$anon$2.run(Incremental.scala:459)
[error] sbt.internal.inc.IncrementalCommon$CycleState.next(IncrementalCommon.scala:116)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:56)
[error] sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:52)
[error] sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:263)
[error] sbt.internal.inc.Incremental$.$anonfun$incrementalCompile$8(Incremental.scala:414)
[error] sbt.internal.inc.Incremental$.withClassfileManager(Incremental.scala:501)
[error] sbt.internal.inc.Incremental$.incrementalCompile(Incremental.scala:401)
[error] sbt.internal.inc.Incremental$.apply(Incremental.scala:167)
[error] sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:528)
[error] sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:482)
[error] sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:332)
[error] sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:420)
[error] sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:137)
[error] sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:2357)
[error] sbt.Defaults$.$anonfun$compileIncrementalTask$2(Defaults.scala:2314)
[error] sbt.internal.io.Retry$.apply(Retry.scala:46)
[error] sbt.internal.io.Retry$.apply(Retry.scala:28)
[error] sbt.internal.io.Retry$.apply(Retry.scala:23)
[error] sbt.internal.server.BspCompileTask$.compute(BspCompileTask.scala:31)
[error] sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:2310)
[error] scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error] sbt.std.Transform$$anon$4.work(Transform.scala:68)
[error] sbt.Execute.$anonfun$submit$2(Execute.scala:282)
[error] sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
[error] sbt.Execute.work(Execute.scala:291)
[error] sbt.Execute.$anonfun$submit$1(Execute.scala:282)
[error] sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
[error] sbt.CompletionService$$anon$2.call(CompletionService.scala:64)
[error] java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
[error] java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error] java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
[error] java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
[error] java.base/java.lang.Thread.run(Thread.java:831)
[error]
[error] stack trace is suppressed; run 'last Test / compileIncremental' for the full output
[error] (Test / compileIncremental) java.lang.NoClassDefFoundError: scala/collection/immutable/List
[error] Total time: 0 s, completed 26 nov. 2021, 13:33:34

Does anyone have any idea about why I get this error ?

I may be wrong but it looks like Scala 3.0.0-M2 get rid of the scala.collection.immutable.List class.

Answer 1

Thanks to @stefanobaghino , it turns out I just have to change my build.sbt file with :

name := "meteo-france-client"

version := "0.1"

scalaVersion := "3.0.2"

libraryDependencies += "org.scalatest" %% "scalatest" % "3.2.10" % Test

Thus switching from Scala 3.0.0-M2 to Scala 3.0.2 and Sclatest 3.3.0-SNAP3 to Scalatest 3.2.10.