On line 133 of the hadoop shell wrapper, CLASSPATH is set as:
Notice that the built-up CLASSPATH, along with all the libs and unwanted JARS are pre-pended BEFORE the user's HADOOP_CLASSPATH. Therefore there is no way to put your own JARs in front of those that the hadoop wrapper script sets.
We propose a patch that reverses this order. Failing that, we would like to add a command line option to override this behavior and enable a user's JARs to be found before the wrong ones in the Hadoop library paths.
We always welcome your opinions.