Apache Maven 3 is required to build Apache Commons Weaver. Things to know:
Apache Commons Weaver uses the japicmp report for API compatibility reporting. This requires that the package goal be invoked in the same Maven run as the site goal. Further, the site generation process runs out of permgen space when built with default JVM settings (on applicable Java versions); the MAVEN_OPTS environment variable can be used to setMaxPermSize.-XX:MaxPermSize=128m` seems to be adequate on Java 7.