Have XJC-Util work with both JAXB 2.1 and JAXB 2.2

When building the CXF-Trunk (mvn install -Pfastinstall) if I have JAXB 2.2 (jaxb-api.jar) in my JDK 6 endorsed directory the cxf-api build fails (possibly others would fail as well) due to the XJC tooling expecting JAXB 2.1:

gmazza@gmazza-work:~/dataExt3/opensource/CXF-TRNK/api$ mvn clean install -Pfastinstall -e
+ Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Apache CXF API
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean

{execution: default-clean}

]
[INFO] Deleting /media/NewDriveExt3/opensource/CXF-TRNK/api/target
[INFO] [dependency:unpack

{execution: unpack-schemas}

]
[INFO] Configured Artifact: org.apache.cxf:cxf-common-schemas:2.4.0-SNAPSHOT:jar
[INFO] Unpacking /home/gmazza/.m2/repository/org/apache/cxf/cxf-common-schemas/2.4.0-SNAPSHOT/cxf-common-schemas-2.4.0-SNAPSHOT.jar to
/media/NewDriveExt3/opensource/CXF-TRNK/api/target/schemas
with includes null and excludes:null
[INFO] [cxf-xml2fastinfoset:xml2fastinfoset

{execution: xml2fastinfoset}

]
[INFO] [cxf-xjc:xsdtojava

{execution: generate-sources}

]
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO]

[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.lifecycle.LifecycleExecutionException
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:719)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:556)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:535)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.MojoExecutionException
at org.apache.cxf.maven_plugin.AbstractXSDToJavaMojo.execute(AbstractXSDToJavaMojo.java:230)
at org.apache.cxf.maven_plugin.XSDToJavaMojo.execute(XSDToJavaMojo.java:38)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
... 17 more
Caused by: java.lang.NullPointerException
at org.apache.cxf.xjc.dv.DefaultValuePlugin.updateSetter(DefaultValuePlugin.java:365)
at org.apache.cxf.xjc.dv.DefaultValuePlugin.run(DefaultValuePlugin.java:165)
at com.sun.tools.xjc.addon.apache_cxf.dv.DefaultValuePlugin.run(DefaultValuePlugin.java:59)
at com.sun.tools.xjc.model.Model.generateCode(Model.java:290)
at com.sun.tools.xjc.Driver.run(Driver.java:343)
at com.sun.tools.xjc.Driver.run(Driver.java:191)
at org.apache.cxf.maven_plugin.AbstractXSDToJavaMojo.execute(AbstractXSDToJavaMojo.java:218)
... 20 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4 seconds
[INFO] Finished at: Fri Dec 17 00:43:24 EST 2010
[INFO] Final Memory: 36M/364M

From the error message above, it's not clear to the newbie builder that JAXB 2.2 is the culprit, adding unnecessary delays as well to this problem.

If the matter cannot be fixed, to somehow return an error message saying "You must use JAXB 2.1 (remove JAXB 2.2 from your endorsed folder)" or similar would be good, at least to speed up troubleshooting.