Debug Scala Macros with Intellij

Question

I have an sbt project which I ran "gen-idea" to setup to work with Intellij 12.4. In one project is my main code an the other project has my macro code. When trying debug my macro via a test file by following http://docs.scala-lang.org/overviews/macros/overview.html but throws:

error: 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$lzycompute(Definitions.scala:181)
at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackage(Definitions.scala:181)
at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass$lzycompute(Definitions.scala:182)
at scala.reflect.internal.Definitions$DefinitionsClass.RuntimePackageClass(Definitions.scala:182)
at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr$lzycompute(Definitions.scala:1015)
at scala.reflect.internal.Definitions$DefinitionsClass.AnnotationDefaultAttr(Definitions.scala:1014)
at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses$lzycompute(Definitions.scala:1144)
at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses(Definitions.scala:1143)
at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode$lzycompute(Definitions.scala:1187)
at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode(Definitions.scala:1187)
at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1252)
at scala.tools.nsc.Global$Run.<init>(Global.scala:1290)
at scala.tools.nsc.Driver.doCompile(Driver.scala:32)
at scala.tools.nsc.Main$.doCompile(Main.scala:79)
at scala.tools.nsc.Driver.process(Driver.scala:54)
at scala.tools.nsc.Driver.main(Driver.scala:67)
at scala.tools.nsc.Main.main(Main.scala)

I have checked to ensure that in my class path that ALL jars from SCALA_HOME/lib/ are included and they are. Btw this is with Scala v2.10.2

Answer 1

I just want to note for future readers that it's also possible to start your sbt in debug mode and then connect the idea debugger remotely.

• start sbt with: sbt -jvm-debug 5005
• create a "Remote" "Run/Debug Config" in idea (defaults to port 5005)

Run the remote-debug config in idea. That will connect it to your running sbt. Then you can set breakpoints in your macro code and when running compile in sbt, idea should stop at the breakpoint.

note: to re-run compile after a successful compile you need either to clean or change some code