Since version 2.3.5 the maven-bundle-plugin is incompatible with the maven-source-plugin. I get the following error message during the maven-sources-plugin:jar goal:
[WARNING] NOT adding sources to artifacts with classifier as Maven only supports one classifier per artifact. Current artifact [<GroupId>:<ArtifactId>:<Version>] has a  classifier.
The problem does not occur with maven-bundle-plugin in version 2.3.4.
You can easily reproduce by creating a project with packaging "bundle" and just configuring the maven-source-plugin like this: