When trying to build the 1.2.15 source from subversion the JMX libraries must be downloaded and installed manually. According to http://forum.java.sun.com/thread.jspa?messageID=10223656 the core libraries are in Java 5 and the tools library should be downloadable from http://opendmk.dev.java.net. Hence I suggest putting the build requirement for log4j to a Java 5+ JVM (but still compile to the appropriate level for backwards compatability) and investigate if the rest could be downloaded automatically by maven.
*** This bug has been marked as a duplicate of bug 44517 ***