show full stack trace by default when running in batch mode

main/LogManager.scala

@@ -39,11 +39,13 @@ object LogManager
 		def getOr[T](key: AttributeKey[T], default: T): T = data.get(scope, key) getOrElse default
 		val screenLevel = getOr(logLevel.key, Level.Info)
 		val backingLevel = getOr(persistLogLevel.key, Level.Debug)
-		val screenTrace = getOr(traceLevel.key, -1)
+		val screenTrace = getOr(traceLevel.key, defaultTraceLevel(state))
 		val backingTrace = getOr(persistTraceLevel.key, Int.MaxValue)
 		val extraBacked = state.globalLogging.backed :: Nil
 		multiLogger( new MultiLoggerConfig(console, backed, extraBacked ::: extra, screenLevel, backingLevel, screenTrace, backingTrace) )
 	}
+	def defaultTraceLevel(state: State): Int =
+		if(state.interactive) -1 else Int.MaxValue
 	def suppressedMessage(key: ScopedKey[_], state: State): SuppressedTraceContext => Option[String] =
 	{
 		lazy val display = Project.showContextKey(state)

main/command/BasicCommands.scala

@@ -118,9 +118,9 @@ object BasicCommands
 		val line = reader.readLine(prompt)
 		line match {
 			case Some(line) =>
-				val newState = s.copy(onFailure = Some(Shell), remainingCommands = line +: Shell +: s.remainingCommands)
+				val newState = s.copy(onFailure = Some(Shell), remainingCommands = line +: Shell +: s.remainingCommands).setInteractive(true)
 				if(line.trim.isEmpty) newState else newState.clearGlobalLog
-			case None => s
+			case None => s.setInteractive(false)
 		}
 	}
 

main/command/BasicKeys.scala

@@ -7,4 +7,5 @@ object BasicKeys
 	val historyPath = AttributeKey[Option[File]]("history", "The location where command line history is persisted.", 40)
 	val shellPrompt = AttributeKey[State => String]("shell-prompt", "The function that constructs the command prompt from the current build state.", 10000)
 	val watch = AttributeKey[Watched]("watch", "Continuous execution configuration.", 1000)
+	private[sbt] val interactive = AttributeKey[Boolean]("interactive", "True if commands are currently being entered from an interactive environment.", 10)
 }

main/command/State.scala

@@ -38,6 +38,13 @@ trait Identity {
 	override final def toString = super.toString
 }
 
+/** StateOps methods to be merged at the next binary incompatible release. */
+private[sbt] trait NewStateOps
+{
+	def interactive: Boolean
+	def setInteractive(flag: Boolean): State
+}
+
 /** Convenience methods for State transformations and operations. */
 trait StateOps {
 	def process(f: (String, State) => State): State
@@ -151,6 +158,11 @@ object State
 		new Reboot(app.scalaProvider.version, state.remainingCommands, app.id, state.configuration.baseDirectory)
 	}
 
+	private[sbt] implicit def newStateOps(s: State): NewStateOps = new NewStateOps {
+		def interactive = s.get(BasicKeys.interactive).getOrElse(false)
+		def setInteractive(i: Boolean) = s.put(BasicKeys.interactive, i)
+	}
+
 	/** Provides operations and transformations on State. */
 	implicit def stateOps(s: State): StateOps = new StateOps {
 		def process(f: (String, State) => State): State =