Akka 2.0.4 pulls in both scala 2.9.1 and 2.9.2

Question

I'm using onejar to build an application that uses scala 2.9.2 and akka 2.0.4. When onejar does the build of my application it reports the following:

[WARNING]  Expected all dependencies to require Scala version: 2.9.2
[WARNING]  org.broadinstitute.workflow:PEMstr:1.0 requires scala version: 2.9.2
[WARNING]  org.broadinstitute.workflow:PEMstr:1.0 requires scala version: 2.9.2
[WARNING]  org.scala-lang:scala-compiler:2.9.2 requires scala version: 2.9.2
[WARNING]  com.typesafe.akka:akka-actor:2.0.4 requires scala version: 2.9.2
[WARNING]  com.typesafe.akka:akka-kernel:2.0.4 requires scala version: 2.9.2
[WARNING]  com.typesafe.akka:akka-remote:2.0.4 requires scala version: 2.9.2
[WARNING]  net.databinder:dispatch-json_2.9.1:0.8.5 requires scala version: 2.9.1
[WARNING] Multiple versions of scala libraries detected!

PEMstr is my application but beyond that I have only included the akka trio and the scala compiler as Maven dependencies. It appears that akka-remote is pulling in netty which is pulling in dispatch-json which is leading to the scala version differences. Can this be prevented? Here are some maven downloads reported during the build...

Downloading: http://scala-tools.org/repo-releases/com/typesafe/akka/akka-remote/2.0.4/akka-remote-2.0.4.jar
Downloading: http://scala-tools.org/repo-releases/io/netty/netty/3.5.4.Final/netty-3.5.4.Final.jar
Downloading: http://scala-tools.org/repo-releases/com/google/protobuf/protobuf-java/2.4.1/protobuf-java-2.4.1.jar
Downloading: http://scala-tools.org/repo-releases/net/debasishg/sjson_2.9.1/0.15/sjson_2.9.1-0.15.jar
Downloading: http://scala-tools.org/repo-releases/net/databinder/dispatch-json_2.9.1/0.8.5/dispatch-json_2.9.1-0.8.5.jar

Thanks.

Answer 1

No, netty doesn't have any dependency. akka-remote is the one having a dependency to sjson.

The only public version of sjson built against 2.9.2 is 0.18, while akka remote uses 0.15: http://search.maven.org/#artifactdetails%7Cnet.debasishg%7Csjson_2.9.2%7C0.18%7Cjar

Depending on your build system, you can force it to use 2.9.2/0.18. For maven (as you're talking about maven dependencies), you'll have to exclude net.debasishg/sjson_2.9.1 from akka-remote, and explicitly import net.debasishg/sjson_2.9.2.