NullPointerException when invoking JUnit using Groovy Ant under Tomcat

The subject line is a mouthful! Here is what I am doing:

I needed a means to invoke JUnit within a web container within the same jvm, so 
that I can pass system properties to the Junit test.  Someone in my department 
suggested using Groovy's Ant integration to invoke JUnit, which I have done. 
When groovy invokes Junit, I get a nasty Exception. Here is a snippet of the 
Tomcat console: 

    [junit] Running com.mycompany.MyTest
    [junit] Tests run: 1, Failures: 0, Errors: 1, Time elapsed: 0 secnull
java.lang.NullPointerException
        at java.io.Writer.write(Writer.java:126)
        at 
org.apache.tools.ant.util.DOMElementWriter.write(DOMElementWriter.java:113)
        at 
org.apache.tools.ant.taskdefs.optional.junit.XMLJUnitResultFormatter.endTestSuite(XMLJUnitResultFormatter.java:135)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.fireEndTestSuite(JUnitTestRunner.java:440)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(JUnitTestRunner.java:313)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.executeInVM(JUnitTask.java:954)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:626)
        at 
org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:600)
        at org.apache.tools.ant.Task.perform(Task.java:364)
        at groovy.util.AntBuilder.nodeCompleted(AntBuilder.java:115)
        at groovy.util.BuilderSupport.doInvokeMethod(BuilderSupport.java:160)
        at groovy.util.BuilderSupport.invokeMethod(BuilderSupport.java:85)
        at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:130)
        at 
org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:106)
        at com.sas.junit.JUnitInvoker.runJUnit(C:\JUnitInvoker.groovy:29)
        at 
gjdk.com.sas.junit.JUnitInvoker_GroovyReflector.invoke(JUnitInvoker_GroovyReflector.java)
        at groovy.lang.MetaMethod.invoke(MetaMethod.java:110)
        at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:1398)
        at groovy.lang.MetaClass.invokeMethod(MetaClass.java:319)
        at 
gjdk.groovy.lang.MetaClass_GroovyReflector.invoke(MetaClass_GroovyReflector.java)
        at groovy.lang.MetaMethod.invoke(MetaMethod.java:110)
        at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:1398)
        at groovy.lang.MetaClass.invokeMethod(MetaClass.java:319)
        at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:143)
        at 
org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:106)
        at com.mycompany.junit.JUnitInvoker.invokeMethod(C:\JUnitInvoker.groovy)
        at com.mycompany.junit.caller.InvokerCaller.callJUnitInvoker(Unknown 
Source)
        at 
com.mycompany.testserver.handler.EmpirixHandler.handleRequest(EmpirixHandler.java:150)
        at 
com.mycompany.testserver.RemoteControlTestService.handleRequest(RemoteControlTestService.java:201)
        at 
com.mycompany.testserver.RemoteControlTestService.doPost(RemoteControlTestService.java:62)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at 
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
        at 
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
        at 
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
        at 
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at 
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at 
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
        at 
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
        at 
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
        at 
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
        at 
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
        at 
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
        at 
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
        at java.lang.Thread.run(Thread.java:534)


>From the following post, it appears that the problem is caused by the Junit 
>testcase name being null:
http://www.diasparsoftware.com/weblog/archives/00000004.html

Well, I think the name is being passed in by groovy (or Ant), when it creates 
the Junit testcase (using the TestCase constructor). 

Does anyone know if this is a Groovy bug, or if perhaps it can be fixed by 
configuration changes, etc?  I have been trying to figure it out for over two 
days.

Thanks,
Trevor