with an ant task configurated like this:

<datanucleusenhancer classpathref="project.classpath" dir="${project.build}" failonerror="true" verbose="true" detachlistener="true">
<jvmarg line="-Dlog4j.configuration=file:src/datanucleus-log4j.properties" />
</datanucleusenhancer>

i have this problem:

[datanucleusenhancer] Exception in thread "main" java.lang.RuntimeException: option -detachListener needs an argument
[datanucleusenhancer] at org.datanucleus.util.CommandLine.parse(CommandLine.java:200)
[datanucleusenhancer] at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1256)