IntelliJ Ideaでgradleのサブブロジェクト構成をビルドするとエラーになる問題

Error:scalac: Error: object scala.runtime in compiler mirror not found.
scala.reflect.internal.MissingRequirementError: object scala.runtime in compiler mirror not found.
	at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:16)
	at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:17)
	at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:48)
	at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40)
	at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61)
	at scala.reflect.internal.Mirrors$RootsBase.getPackage(Mirrors.scala:172)
	at scala.reflect.internal.Mirrors$RootsBase.getRequiredPackage(Mirrors.scala:175)
	at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackage$lzycompute(Definitions.scala:183)
	at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackage(Definitions.scala:183)
	at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass$lzycompute(Definitions.scala:184)
	at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass(Definitions.scala:184)
	at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr$lzycompute(Definitions.scala:1024)
	at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr(Definitions.scala:1023)
	at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses$lzycompute(Definitions.scala:1153)
	at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses(Definitions.scala:1152)
	at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode$lzycompute(Definitions.scala:1196)
	at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode(Definitions.scala:1196)
	at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1261)
	at scala.tools.nsc.Global$Run.<init>(Global.scala:1290)
	at xsbt.CachedCompiler0$$anon$2.<init>(CompilerInterface.scala:116)
	at xsbt.CachedCompiler0.run(CompilerInterface.scala:116)
	at xsbt.CachedCompiler0.run(CompilerInterface.scala:102)
	at xsbt.CompilerInterface.run(CompilerInterface.scala:27)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:102)
	at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:48)
	at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:41)
	at org.jetbrains.jps.incremental.scala.local.IdeaIncrementalCompiler.compile(IdeaIncrementalCompiler.scala:28)
	at org.jetbrains.jps.incremental.scala.local.LocalServer.compile(LocalServer.scala:25)
	at org.jetbrains.jps.incremental.scala.remote.Main$.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.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 com.martiansoftware.nailgun.NGSession.run(NGSession.java:319)

対応方法

$ cd {project_root}
$ find . -name "*.iml" | xargs rm -rf      #idea設定を全削除
$ find . -name ".idea" | xargs rm -rf      # ideaプロジェクト設定を削除
$ gradle clean                                       # gradleきれいにしてから
$ gradle build -x test                          # 一度、全ビルドしてからの
$ gradle idea                                        # idea設定を作成