Play2系でplayコマンド実行時にsbtが無いと言われる場合の対処法

Play! Java

下記のようなエラーが発生したときは、project/build.propertiesのsbtのバージョンを確認すること。
ソースは古いplayのままでframework側のsbtが新しいかもしれない。
project/build.properties内のsbtバージョンを正しいバージョンに書き換えれば動く。

$ play run
Picked up _JAVA_OPTIONS: -Xms1024m -Xmx1024m
Getting org.scala-sbt sbt 0.11.3 ...

:: problems summary ::
:::: WARNINGS
		module not found: org.scala-sbt#sbt;0.11.3

	==== local: tried

	  /Users/Shared/play-2.1-RC3/repository/local/org.scala-sbt/sbt/0.11.3/ivys/ivy.xml

	==== Maven2 Local: tried

	  file:///Users/kurodaitsuki/.m2/repository/org/scala-sbt/sbt/0.11.3/sbt-0.11.3.pom

	==== typesafe-ivy-releases: tried

	  http://repo.typesafe.com/typesafe/ivy-releases/org.scala-sbt/sbt/0.11.3/ivys/ivy.xml

	==== Maven Central: tried

	  http://repo1.maven.org/maven2/org/scala-sbt/sbt/0.11.3/sbt-0.11.3.pom

		::::::::::::::::::::::::::::::::::::::::::::::

		::          UNRESOLVED DEPENDENCIES         ::

		::::::::::::::::::::::::::::::::::::::::::::::

		:: org.scala-sbt#sbt;0.11.3: not found

		::::::::::::::::::::::::::::::::::::::::::::::



:: USE VERBOSE OR DEBUG MESSAGE LEVEL FOR MORE DETAILS
unresolved dependency: org.scala-sbt#sbt;0.11.3: not found
Error during sbt execution: Error retrieving required libraries
  (see /Users/Shared/play-2.1-RC3/framework/sbt/boot/update.log for complete log)
Error: Could not retrieve sbt 0.11.3