val printVers = TaskKey[Unit]("printvers")
val printVersTask = TaskKey[Unit]("printvers") <<= {version map println}

def publishSnapshot = Command.command("publish-snapshot") { state =>
  val newState = SessionSettings.reapply(state.get(sessionSettings).get.appendRaw(version := "<><>"), state)
  Project.runTask(printVers in Compile, newState, true)

  state
}

lazy val root = Project("main", file("."),
                        settings =
                          Defaults.defaultSettings ++
                          Seq(printVersTask)).settings(commands += publishSnapshot)