Error building assembly in branch activemq-4.0

Exception thrown:

This artifact might be in your project's POM, or it might have been included transitively during the resolution process. Here is the information we do have for this artifact:

o GroupID: incubator-activemq
o ArtifactID: incubator-activemq
o Version: 4.0.2-SNAPSHOT
o Type: jar

[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.artifact.InvalidArtifactRTException: For artifact

{incubator-activemq:incubator-activemq:4.0.2-SNAPSHOT:jar}

: An attached artifact must have a different ID than its corresponding main artifact.
at org.apache.maven.project.artifact.AttachedArtifact.<init>(AttachedArtifact.java:48)
at org.apache.maven.project.DefaultMavenProjectHelper.attachArtifact(DefaultMavenProjectHelper.java:50)
at org.apache.maven.plugin.assembly.AbstractAssemblyMojo.createAssembly(AbstractAssemblyMojo.java:290)