NPE in ValueCustom.fillType()

I had a NullPointerException when Maven+Jibx2Wsdl converted a simple class with a custom mapping; stacktrace is:
[echo] Converting Java code to WSDL, xsd and binding.xml
[java] Exception in thread "main" java.lang.NullPointerException
[java] at org.jibx.custom.classes.ValueCustom.fillType(ValueCustom.java:491)
[java] at org.jibx.custom.classes.ClassCustom.apply(ClassCustom.java:831)
[java] at org.jibx.custom.classes.PackageCustom.apply(PackageCustom.java:147)
[java] at org.jibx.custom.classes.GlobalCustom.fillClasses(GlobalCustom.java:469)
[java] at org.jibx.ws.wsdl.tools.WsdlGeneratorCommandLine.applyOverrides(WsdlGeneratorCommandLine.java:187)
[java] at org.jibx.custom.CustomizationCommandLineBase.processArgs(CustomizationCommandLineBase.java:186)
[java] at org.jibx.ws.wsdl.tools.Jibx2Wsdl.main(Jibx2Wsdl.java:552)

Looking into the source code (fresh CVS checkout), I found the following lines:
ClassCustom.apply(), line 830+:

ValueCustom cust = (ValueCustom)namemap.get(name);
cust.fillType(null, req, style);

and ValueCustom.fillType(), line 490+:

/* package */void fillType(IClass info, Boolean req, Integer style) {
String type = info.getName();

So the ClassCustom line 831 call always leads a NPE, as info is null...