error handling adjustments, including showing failing task in red (for #29)

main/EvaluteTask.scala

@@ -8,6 +8,7 @@ package sbt
 	import Keys.{streams, Streams, TaskStreams}
 	import Keys.{dummyState, dummyStreamsManager, parseResult, resolvedScoped, streamsManager, taskDefinitionKey}
 	import Scope.{GlobalScope, ThisScope}
+	import scala.Console.{RED, RESET}
 
 object EvaluateTask
 {
@@ -48,7 +49,11 @@ object EvaluateTask
 			getStreams(key, streams).log.trace(ex)
 		log.error("Incomplete tasks (run 'last <task>' for the full log):")
 		for( (key, msg, ex) <- keyed if(msg.isDefined || ex.isDefined) )
-			getStreams(key, streams).log.error("  " + Project.display(key) + ": " + (msg.toList ++ ex.toList).mkString("\n\t"))
+		{
+			val msgString = (msg.toList ++ ex.toList.map(ErrorHandling.reducedToString)).mkString("\n\t")
+			val keyString = if(log.ansiCodesSupported) RED + key.key.label + RESET else key.key.label
+			getStreams(key, streams).log.error("  " + Scope.display(key.scope, keyString) + ": " + msgString)
+		}
 		for(u <- un)
 			log.debug(u.toString)
 	}

main/Main.scala

@@ -15,6 +15,7 @@ package sbt
 	import scala.collection.JavaConversions._
 	import Function.tupled
 	import java.net.URI
+	import java.lang.reflect.InvocationTargetException
 	import Path._
 
 	import java.io.File
@@ -380,15 +381,20 @@ object BuiltinCommands
 		{
 			case _: Incomplete => () // already handled by evaluateTask
 			case _: NoMessageException => ()
-			case _: MessageOnlyException =>
-				log.error(e.toString)
-			case _ =>
-				log.trace(e)
-				log.error(e.toString)
-				log.error("Use 'last' for the full log.")
+			case ite: InvocationTargetException =>
+				val cause = ite.getCause
+				if(cause == null || cause == ite) logFullException(ite, log) else handleException(cause, s, log)
+			case _: MessageOnlyException => log.error(e.toString)
+			case _ => logFullException(e, log)
 		}
 		s.fail
 	}
+	def logFullException(e: Throwable, log: Logger)
+	{
+		log.trace(e)
+		log.error(ErrorHandling reducedToString e)
+		log.error("Use 'last' for the full log.")
+	}
 	
 	def addAlias(s: State, name: String, value: String): State =
 		if(Command validID name) {

util/control/ErrorHandling.scala

@@ -21,6 +21,15 @@ object ErrorHandling
 	def convert[T](f: => T): Either[Exception, T] =
 		try { Right(f) }
 		catch { case e: Exception => Left(e) }
+
+	def reducedToString(e: Throwable): String =
+		if(e.getClass == classOf[RuntimeException])
+		{
+			val msg = e.getMessage
+			if(msg == null || msg.isEmpty) e.toString else msg
+		}
+		else
+			e.toString
 }
 final class TranslatedException private[sbt](msg: String, cause: Throwable) extends RuntimeException(msg, cause)
 {