Experiment indicates that this problem is really very, very deep.
If I run Gant then xercesImpl.jar and xml-apis.jar are in the rootloader
classpath picked up from the Ant jar store. This leads to the
java.lang.LinkageError. If the jars are put into the $GROOVY_HOME/lib
then everything works fine. If the jars are put in ~/.groovy/lib then
it is broken again. This implies the classloader lookup problem is
associated with when jars are put into the classpath. If it happens at
Groovy boot initialization time then things are fine, if they are loaded
after teh first initialization then there is a problem.
Dr Russel Winder Partner