I make a maven aggregator project with two modules.
The first module is a dependency of the second.
The first module is build with the install goal.
The second with the shade plugin during the package phase.
The first module build runs successfully and install resulting jar file in the maven local repository.
The second module build fails with this error :
It's due to the shade plugin whose tries to reference first module classes from target/classes repository instead of the jar file previously build.
Therefore, it seems that the shade plugin doesn't work with a maven multimodules project.
I manage to build my maven aggregator project by applying the attached patch (patch-maven-shade-plugin.txt) on the class ShadeMojo.java