The Findbugs plugin sets the system varaible to the a non standard sax parser.

It helpfully adds the sax parser to its context classpath.

When some part of a maven build wishes to use a sax parser it blows up as it can not load the non-existent sax parser.

Findbugs should not set the sax parser and use whatever is returned using the standard JDK APIs.

INFO] Generating "Project Summary" report.
[INFO] Generating "About" report.
[INFO] Generating "FindBugs Report" report.
[INFO] Using source root:
[INFO] /home/hudson/data/workspace/xxx-app_full/trunk/xxx-app-common/xxx-app-common-core/target/classes
[INFO] Using test source root:
[INFO] /home/hudson/data/workspace/xxx-app_full/trunk/xxx-app-common/xxx-app-common-core/target/test-classes
[INFO] Using maximum effort.
[INFO] Adding Source Directory: /home/hudson/data/workspace/xxx-app_full/trunk/xxx-app-common/vam-app-common-core/src/main/java
[INFO] Using low threshold.
[INFO] Using FindBugs Version: 1.3.7
[INFO] Using low threshold.
[INFO] Using low threshold.
[INFO] Using low threshold.
[INFO] Using the xdoc format
[INFO] Using maximum effort.
[INFO] Using low threshold.
[INFO] Using low threshold.
[INFO] Debugging is Off
[INFO] No bug include filter.
[INFO] Using bug exclude filter /tmp/plexus-resources178441232tmp
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] A java source file could not be added

Embedded error: SAX2 driver class org.apache.xerces.parsers.SAXParser not found
[INFO] ------------------------------------------------------------------------
[INFO] Trace
java.lang.reflect.UndeclaredThrowableException
at $Proxy10.generate(Unknown Source)
at org.apache.maven.plugins.site.ReportDocumentRenderer.renderDocument(ReportDocumentRenderer.java:139)
at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.renderModule(DefaultSiteRenderer.java:303)
at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.render(DefaultSiteRenderer.java:135)
at org.apache.maven.plugins.site.SiteMojo.renderLocale(SiteMojo.java:133)
at org.apache.maven.plugins.site.SiteMojo.execute(SiteMojo.java:100)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
at hudson.maven.agent.PluginManagerInterceptor.executeMojo(PluginManagerInterceptor.java:182)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
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.lifecycle.LifecycleExecutorInterceptor.execute(LifecycleExecutorInterceptor.java:65)
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 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 hudson.maven.agent.Main.launch(Main.java:165)
at hudson.maven.MavenBuilder.call(MavenBuilder.java:165)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:694)
at hudson.maven.MavenModuleSetBuild$Builder.call(MavenModuleSetBuild.java:638)
at hudson.remoting.UserRequest.perform(UserRequest.java:114)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:270)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: org.apache.maven.plugin.MojoExecutionException: A java source file could not be added
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.codehaus.groovy.runtime.MetaClassHelper.doConstructorInvoke(MetaClassHelper.java:535)
at groovy.lang.MetaClassImpl.doConstructorInvoke(MetaClassImpl.java:2356)
at groovy.lang.MetaClassImpl.invokeConstructor(MetaClassImpl.java:1255)
at groovy.lang.MetaClassImpl.invokeConstructor(MetaClassImpl.java:1185)
at org.codehaus.groovy.runtime.InvokerHelper.invokeConstructorOf(InvokerHelper.java:809)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeNewN(ScriptBytecodeAdapter.java:230)
at org.codehaus.mojo.findbugs.FindBugsMojo.fail(FindBugsMojo.groovy:1187)
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.groovy.reflection.CachedMethod.invoke(CachedMethod.java:86)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:230)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:912)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnCurrentN(ScriptBytecodeAdapter.java:78)
at org.codehaus.mojo.findbugs.FindBugsMojo.executeReport(FindBugsMojo.groovy:771)
at org.apache.maven.reporting.AbstractMavenReport.generate(AbstractMavenReport.java:101)
at sun.reflect.GeneratedMethodAccessor72.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at hudson.maven.agent.ComponentInterceptor.invoke(ComponentInterceptor.java:47)
at hudson.maven.agent.PluginManagerInterceptor$3.invoke(PluginManagerInterceptor.java:229)
... 37 more
Caused by: java.io.IOException: SAX2 driver class org.apache.xerces.parsers.SAXParser not found
at edu.umd.cs.findbugs.filter.Filter.<init>(Filter.java:128)
at edu.umd.cs.findbugs.FindBugs.configureFilter(FindBugs.java:389)
at edu.umd.cs.findbugs.FindBugs2.addFilter(FindBugs2.java:314)
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.groovy.reflection.CachedMethod.invoke(CachedMethod.java:86)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:230)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:912)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:756)
at org.codehaus.groovy.runtime.InvokerHelper.invokePogoMethod(InvokerHelper.java:778)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:758)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodN(ScriptBytecodeAdapter.java:170)
at org.codehaus.mojo.findbugs.FindBugsMojo.addFiltersToFindBugs(FindBugsMojo.groovy:564)
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.groovy.reflection.CachedMethod.invoke(CachedMethod.java:86)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:230)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:912)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnCurrentN(ScriptBytecodeAdapter.java:78)
at org.codehaus.mojo.findbugs.FindBugsMojo.initialiseFindBugs(FindBugsMojo.groovy:1063)
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.groovy.reflection.CachedMethod.invoke(CachedMethod.java:86)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:230)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:912)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnCurrentN(ScriptBytecodeAdapter.java:78)
at org.codehaus.mojo.findbugs.FindBugsMojo.executeReport(FindBugsMojo.groovy:767)
... 43 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5 minutes 11 seconds
[INFO] Finished at: Tue Oct 26 22:13:35 UTC 2010
[INFO] Final Memory: 120M/254M
[INFO] ------------------------------------------------------------------------