Still having that problem.
I still want to use an subproject that's packed into a JAR file, is there a way to use it in a build.sbt like:
lazy val sub = project.in(file("lib/subproject-SNAPSHOT.jar"))
.enablePlugins(PlayJava, PlayEbean)
This gives me an error message, that the path is no directory (well, that's right). Is there a way to use a subproject in a JAR file?