When running the RAT 0.8 maven plugin from command line (no POM entry for the plugin) in a Eclipse+Maven project which is checked out from .git/ the plugin will not by default exclude the repository dotdir.
C:\ws\proj>\ws\apache-maven-3.0.4\bin\mvn -s ..\empty.xml org.apache.rat:apache-rat-plugin:check
[INFO] — apache-rat-plugin:0.8:check (default-cli) @ et-otp —
[INFO] No excludes
The excludes should eighter be contained in the eclipse defaults or have its own dotfile or scm category. A workaround would be to specify the excludes, unfortunatelly there seems to be no expression associated with the exclude property of the mojo.