Since IIRC maven 2.0.8, -Dmaven.test.skip has been replaced by -DskipTests.
Use skipTests (see README.txt).

If you're were still using the maven.test.skip, you 'll now find out that the build fails on drools-compiler
because drools-compiler has a test-jar dependency on drools-core (as well as a normal dependency on drools-core).

The skipTests compiles and builds the test-jars (just doesn't run the tests),
while maven.test.skip doesn't even compile or build the test-jars (which is not much faster).

-- 
With kind regards,
Geoffrey De Smet