XStream failes on GNU libgcj 4.3.2 with DurationConverter

The following (shortend) stacktrace says it all:

com.thoughtworks.xstream.XStream$InitializationException: Could not instantiate converter : com.thoughtworks.xstream.converters.extended.DurationConverter : null
at com.thoughtworks.xstream.XStream.dynamicallyRegisterConverter(XStream.java:732)
at com.thoughtworks.xstream.XStream.setupConverters(XStream.java:696)
at com.thoughtworks.xstream.XStream.<init>(XStream.java:445)
...
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance(libgcj.so.90)
at com.thoughtworks.xstream.XStream.dynamicallyRegisterConverter(XStream.java:725)
...61 more
Caused by: javax.xml.datatype.DatatypeConfigurationException: java.lang.ClassNotFoundException: gnu.xml.datatype.JAXPDatatypeFactory
at javax.xml.datatype.DatatypeFactory.newInstance(libgcj.so.90)
at com.thoughtworks.xstream.converters.extended.DurationConverter.<init>(DurationConverter.java:33)
at java.lang.reflect.Constructor.newInstance(libgcj.so.90)
...62 more
Caused by: java.lang.ClassNotFoundException: gnu.xml.datatype.JAXPDatatypeFactory
at java.lang.Class.forName(libgcj.so.90)
at javax.xml.datatype.DatatypeFactory.newInstance(libgcj.so.90)
...64 more

Since javax.xml.datatype.Duration is on the classpath, XStream will try to create a javax.xml.datatype.DatatypeFactory. On gcj this factory is configured to utilize gnu.xml.datatype.JAXPDatatypeFactory, which itself is not present .

So strictly speaking it is gcj's fault. But why does XStream fail so badly because of one failing 'optional' converter?

Workaround: overwrite setupAliases() and catch InitializationExceptions.

Note that this issue is related to but not the same as http://jira.codehaus.org/browse/XSTR-537 .