translate Uninitialized message to use 'display'

main/Build.scala

@@ -232,7 +232,7 @@ object Load
 		lazy val rootEval = lazyEval(loaded.units(loaded.root).unit)
 		val settings = config.injectSettings ++ buildConfigurations(loaded, getRootProject(projects), rootEval)
 		val delegates = config.delegates(loaded)
-		val data = Project.make(settings)(delegates)
+		val data = Project.makeSettings(settings, delegates)
 		val index = structureIndex(data)
 		val streams = mkStreams(projects, loaded.root, data)
 		(rootEval, new BuildStructure(projects, loaded.root, settings, data, index, streams, delegates))
@@ -244,7 +244,7 @@ object Load
 		// Reevaluates settings after modifying them.  Does not recompile or reload any build components.
 	def reapply(newSettings: Seq[Setting[_]], structure: BuildStructure): BuildStructure =
 	{
-		val newData = Project.make(newSettings)(structure.delegates)
+		val newData = Project.makeSettings(newSettings, structure.delegates)
 		val newIndex = structureIndex(newData)
 		val newStreams = mkStreams(structure.units, structure.root, newData)
 		new BuildStructure(units = structure.units, root = structure.root, settings = newSettings, data = newData, index = newIndex, streams = newStreams, delegates = structure.delegates)

main/Project.scala

@@ -63,6 +63,7 @@ object Project extends Init[Scope]
 		val newAttrs = s.attributes.put(Watch.key, makeWatched(data, ref, project)).put(HistoryPath.key, historyPath)
 		s.copy(attributes = newAttrs)
 	}
+	def makeSettings(settings: Seq[Setting[_]], delegates: Scope => Seq[Scope]) = translateUninitialized( make(settings)(delegates) )
 
 	def makeWatched(data: Settings[Scope], ref: ProjectRef, project: Project): Watched =
 	{
@@ -85,6 +86,12 @@ object Project extends Init[Scope]
 		val f = mapScope(g)
 		ss.map(_ mapKey f mapReferenced f)
 	}
+	def translateUninitialized[T](f: => T): T =
+		try { f } catch { case u: Project.Uninitialized =>
+			val msg = "Uninitialized reference to " + display(u.key) + " from " + display(u.refKey)
+			throw new Uninitialized(u.key, u.refKey, msg)
+		}
+
 
 	val SessionKey = AttributeKey[SessionSettings]("session-settings")
 	val StructureKey = AttributeKey[Load.BuildStructure]("build-structure")

util/collection/Settings.scala

@@ -111,7 +111,7 @@ trait Init[Scope]
 		val scache = PMap.empty[ScopedKey, ScopedKey]
 		def resolve(search: Seq[Scope]): ScopedKey[T] =
 			search match {
-				case Seq() => throw new Uninitialized(k)
+				case Seq() => throw Uninitialized(k, refKey)
 				case Seq(x, xs @ _*) =>
 					val sk = ScopedKey(x, k.key)
 					scache.getOrUpdate(sk, if(defines(sMap, sk, refKey)) sk else resolve(xs))
@@ -137,7 +137,9 @@ trait Init[Scope]
 		}
 	}
 
-	final class Uninitialized(key: ScopedKey[_]) extends Exception("Update on uninitialized setting " + key.key.label + " (in " + key.scope + ")")
+	final class Uninitialized(val key: ScopedKey[_], val refKey: ScopedKey[_], msg: String) extends Exception(msg)
+	def Uninitialized(key: ScopedKey[_], refKey: ScopedKey[_]): Uninitialized =
+		new Uninitialized(key, refKey, "Reference to uninitialized setting " + key.key.label + " (in " + key.scope + ") from " + refKey.key.label +" (in " + refKey.scope + ")")
 	final class Compiled(val dependencies: Iterable[ScopedKey[_]], val eval: Settings[Scope] => Settings[Scope])
 
 	sealed trait Setting[T]