sbt uninitialized sources setting

Build.scala

import sbt._
import Keys._

object Test extends Build {

  lazy val listSources = TaskKey[Unit]("list-sources")

  def listSourcesTask =
    listSources <<= sources map { _ foreach println }

  lazy val root = Project(
    "root",
    file("."),
    settings = Defaults.defaultSettings ++ Seq(listSourcesTask)
  )
}