force REPL startup to be synchronous. fixes #175.

compile/interface/ConsoleInterface.scala

@@ -14,8 +14,8 @@ class ConsoleInterface
 	def run(args: Array[String], bootClasspathString: String, classpathString: String, initialCommands: String, loader: ClassLoader, bindNames: Array[String], bindValues: Array[Any], log: Logger)
 	{
 		val options = args.toList
-		lazy val interpreterSettings = xsbt.MakeSettings(options, log)
+		lazy val interpreterSettings = MakeSettings.sync(options, log)
-		val compilerSettings = xsbt.MakeSettings(options, log)
+		val compilerSettings = MakeSettings.sync(options, log)
 		
 		if(!bootClasspathString.isEmpty)
 			compilerSettings.bootclasspath.value = bootClasspathString
@@ -61,4 +61,18 @@ object MakeSettings
 		else
 			throw new InterfaceCompileFailed(Array(), Array(), command.usageMsg)
 	}
+
+	def sync(options: List[String], log: Logger) =
+	{
+		val settings = apply(options, log)
+
+		// -Yrepl-sync is only in 2.9.1+
+		final class Compat {
+			def Yreplsync = settings.BooleanSetting("-Yrepl-sync", "For compatibility only.")
+		}
+		implicit def compat(s: Settings): Compat = new Compat
+
+		settings.Yreplsync.value = true
+		settings
+	}
 }

main/ConsoleProject.scala

@@ -8,7 +8,7 @@ package sbt
 
 object ConsoleProject
 {
-	def apply(state: State, extra: String, options: Seq[String] = "-Yrepl-sync" :: Nil)(implicit log: Logger)
+	def apply(state: State, extra: String, options: Seq[String] = Nil)(implicit log: Logger)
 	{
 		val extracted = Project extract state
 		val bindings = ("currentState" -> state) :: ("extracted" -> extracted ) :: Nil