IDEA Scala: could not find output directory

Question

Trying to play with scala in IDEA using the scala plugin:

My HelloWorld object:

object HelloWorld { def main(args: Array[String]) { println("Hello") } } 

And sometimes . I get the following error when I click "Run HelloWorld" from the context menu.

  scalac: Error: Could not find an output directory for /Users/username/Work/src/sandbox/src/HelloWorld.scala in List((/Users/username/work/src/sandbox/src,/Users/username/work/src/sandbox/out/production/sandbox)) scala.reflect.internal.FatalError: Could not find an output directory for /Users/username/Work/src/sandbox/src/HelloWorld.scala in List((/Users/username /work/src/sandbox/src,/Users/username/work/src/sandbox/out/production/sandbox)) at scala.tools.nsc.settings.MutableSettings$OutputDirs.outputDirFor(MutableSettings.scala:303) at scala.tools.nsc.backend.jvm.BytecodeWriters$class.outputDirectory(BytecodeWriters.scala:26) at scala.tools.nsc.backend.jvm.BytecodeWriters$class.scala$tools$nsc$backend$jvm$BytecodeWriters$$getFile(BytecodeWriters.scala:37) at scala.tools.nsc.backend.jvm.BytecodeWriters$ClassBytecodeWriter$class.writeClass(BytecodeWriters.scala:89) at scala.tools.nsc.backend.jvm.GenASM$AsmPhase$$anon$4.writeClass(GenASM.scala:67) at scala.tools.nsc.backend.jvm.GenASM$JBuilder.writeIfNotTooBig(GenASM.scala:458) at scala.tools.nsc.backend.jvm.GenASM$JMirrorBuilder.genMirrorClass(GenASM.scala:2954) at scala.tools.nsc.backend.jvm.GenASM$AsmPhase.run(GenASM.scala:113) at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1583) at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1557) at scala.tools.nsc.Global$Run.compileSources(Global.scala:1553) at scala.tools.nsc.Global$Run.compile(Global.scala:1662) at xsbt.CachedCompiler0.run(CompilerInterface.scala:126) at xsbt.CachedCompiler0.run(CompilerInterface.scala:102) at xsbt.CompilerInterface.run(CompilerInterface.scala:27) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:102) at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:48) at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:41) at org.jetbrains.jps.incremental.scala.local.IdeaIncrementalCompiler.compile(IdeaIncrementalCompiler.scala:26) at org.jetbrains.jps.incremental.scala.local.LocalServer.compile(LocalServer.scala:25) at org.jetbrains.jps.incremental.scala.remote.Main$.make(Main.scala:58) at org.jetbrains.jps.incremental.scala.remote.Main$.nailMain(Main.scala:21) at org.jetbrains.jps.incremental.scala.remote.Main.nailMain(Main.scala) at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.martiansoftware.nailgun.NGSession.run(NGSession.java:319) 

This error is very annoying, because to fix it I need to restart IDEA, clean / compile my project, add / remove startup configuration several times. Also, the correct command from the error can be executed manually from the terminal.

Answer 1

Looking at the error comment:

Could not find output directory for:
/ Users / username / Work /src/sandbox/src/HelloWorld.scala

in

• / Users / username / job / SRC / Sandbox / CSI
• / Users / username / job / SRC / Sandbox / exit / production / sandbox

Depending on the environment in which you work, IntelliJ has an upper / lower case value. Make sure the user.home property is set correctly.

Answer 2

From Norbert Radik did not contact me. The paths were true in my case. I had to delete the target/scala-2.11/test-classes folder in order to force Intellij to recompile the test class. A bit of pain, although it will work until I need to modify the test itself. So it’s not really a solution, but a little hack if you really need to debug the test.