Duplicate mappings for scala-library-2.10.3.jar with sbt-native-packager 0.7+, Play 2.2.6 and Scala 2.10

[mslinn]

I'm stuck with Play 2.2.6 and Scala 2.10 for a project. sbt-native-packager 0.6.4 is compatible, but has a bug I can't live with (passing a relative path to scriptClasspath throws java.lang.IllegalArgumentException: character to be escaped is missing). I see this got fixed in sbt-native-packager 0.7.0.

Unfortunately, when I try the sbt stage task using sbt-native-packager 0.7.0 or later I get:

java.lang.RuntimeException: Duplicate mappings:
/work/myProject/target/universal/stage/lib/org.scala-lang.scala-library-2.10.3.jar
from
/opt/play-2.2.6/repository/local/org.scala-lang/scala-library/2.10.3/jars/scala-library.jar
/home/mslinn/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.10.3.jar

Suggestions?

[muuki88]

Sorry for the late reply. This bug seems a bit deeper in sbt. Currently I have no idea what causes this :(

[mslinn]

This bug is causing us a lot of grief. I reached out to @jsuereth a few weeks ago regarding this issue but got no reply.

[muuki88]

I imagine it does, but this is an open source project and we have as much resources as our community provides. If you need any help on debugging this, you can seek guidance, we are happy to help.

@ahjohannessen provided a repo to reproduce the bug (see chat log here)

[mslinn]

I took a shortcut and patched the 0.6 branch so I could fix the error there. Here is the forked GitHub project, complete with instructions on how to install it.

[muuki88]

I took a look where these bindings come from. With the repo mentioned above, I found that spray jars are added as bundle and jar. Adding this to the build.sbt reveales:

val showMappings = taskKey[Unit]("showMappings") 

showMappings := {
  (mappings in Universal).value
  .filter(_._2 contains "spray")
  .foreach {
    case (file, path) => println(file + " -> " + path)
  }
}

sbt universal:showMappings
..io.spray/spray-json_2.11/jars/spray-json_2.11-1.3.1-sources.jar -> lib/io.spray.spray-json_2.11-1.3.1-sources.jar
..io.spray/spray-json_2.11/jars/spray-json_2.11-1.3.1.jar -> lib/io.spray.spray-json_2.11-1.3.1.jar
..io.spray/spray-client_2.11/jars/spray-client_2.11-1.3.2-sources.jar -> lib/io.spray.spray-client_2.11-1.3.2-sources.jar
..io.spray/spray-client_2.11/jars/spray-client_2.11-1.3.2.jar -> lib/io.spray.spray-client_2.11-1.3.2.jar
..io.spray/spray-can_2.11/bundles/spray-can_2.11-1.3.2.jar -> lib/io.spray.spray-can_2.11-1.3.2.jar
..io.spray/spray-io_2.11/bundles/spray-io_2.11-1.3.2.jar -> lib/io.spray.spray-io_2.11-1.3.2.jar
..io.spray/spray-util_2.11/bundles/spray-util_2.11-1.3.2.jar -> lib/io.spray.spray-util_2.11-1.3.2.jar
..io.spray/spray-http_2.11/bundles/spray-http_2.11-1.3.2.jar -> lib/io.spray.spray-http_2.11-1.3.2.jar
..io.spray/spray-httpx_2.11/bundles/spray-httpx_2.11-1.3.2.jar -> lib/io.spray.spray-httpx_2.11-1.3.2.jar

Question is. Why are jars and bundles in these mappings. I guess this in the same issue for the scala library.

[yfyf]

Perhaps obvious, but disabling cached resolution seems to resolve this at least for me. YMMV.

[peter-fu]

Same here, enabled cached resolution today with sbt 0.13.12 and the error "Duplicate mappings" occurred for activator stage.

Play 2.3.10
sbt 0.13.2
sbt-native-packager 1.1.4

Workaround, same as @yfyf, disable cached resolution before activator stage.