When running mvn install on my project, i see it fail due to the following errors:
C:\\Repositories\\blah\\src\\test\\java\\com\\xxx\\qm\\testru
You are most likely using OpenJDK where the source level is 1.3 when not explicitly set - as opposed to Oracle JDK where the source level is 1.5.
Since most modern Java projects target newer code than Java 5 you most likely need to set this anyway.
Also note that if you need a lower target than source (e.g. for compiling with Java 6 but deploying to Java 5) you can do this by using the Eclipse compiler instead of Javac.