I had several recent Issues with Jenkins and Maven I hope this will help someone else out there with the same issue.
Issue:
Jenkins Maven Jobs fail to Parse POMS
Caused by: java.lang.ClassNotFoundException: org.apache.maven.cli.MavenLoggerManager
or
java.lang.NoClassDefFoundError: org/sonatype/guice/bean/reflect/ClassSpace
Discussion:
It appears that Maven 3.1.0, and 3.1.1 (I tried both) have not been compiled into Jenkins yet.
More can be found here: as of today 10/25/2013 the fix version has not been set. So I'm guessing it will be fixed soon.
Solution:
Roll back Maven to 3.0.5, This assumes that you installed maven yourself,(ie /usr/local/maven) rather than having Jenkins do it for you which I didn't try.