The package-info.java files can not be compiled in Maven 2 if the 2.0.2 maven-compiler-plugin is used. package-info.java files can be compiled by earlier versions of the maven-compiler-plugin (I have tried 2.0 and 2.0.1). Newer snapshot versions does not work also and it fails in the same error (I have tried version 2.1-snapshot).
This problem can be caused by an unusual behavior of the javac from jdk 1.5. This behavior is as follows:
You can not use '/' file separator during compiling package-info.java (for instance "javac sk/forro/package-info.java"). You must use '\' separator (for instance "javac sk\forro\package-info.java"). If you use the '/' separator you get the the compilation error reported by this bug (package annotations should be in file package-info.java). This is javac 'feature' has been removed in jdk 6 and in jdk 6 you can use either '/' or '\' - it does not matter.
It looks like the maven-compiler-plugin or one of its components (I mean plexus-x artefacts used by maven-compiler-plugin) uses '/' instead of the '\' in the MS Windows environment.
I have attached a log file of an unsuccessful build (generated by mvn install -X)
A possible workaround to solve this problem temporarily:
The compilation successes if I use either an older version of maven-compiler-plugin or jdk 6 or do not use package-info.java files at all.