DRLVM build is broken since there is no serializer.jar in ant classpath. Xalan is taken from the official xalan mirrow (http://www.reverse.net/pub/apache/xml/xalan-j/xalan-j_2_7_0-bin.zip) in DRLVM build, and the needed class is in serializer.jar, not xalan.jar. All the jars from the xalan-j_2_7_0-bin.zip distributive were put in ant classpath in build.bat/sh, but two days ago build.* was changed so that selializer.jar is not copied to make/tmp. So now the DRLVM build couldn't find the org/apache/xml/serializer/SerializerTrace class.
BTW: the Harmoy classlib xalan.far is taken from http://www.ibiblio.org site, and everythig is OK, org/apache/xml/serializer/SerializerTrace class is present here. So the solution is change the DRLVM build to use the classlib xalan.jar instead the old one.