Hi, 
Reporting Regression with Struts 2.x in RC10 and 8.0.1. The last known working version was RC5.
The exception happens during deploy. I have attached our sample application. 

Known affected struts versions: 2.1.8, 2.2.3, 2.3.8



java.lang.NullPointerException
        at com.opensymphony.xwork2.util.finder.UrlSet.<init>(UrlSet.java:71)
        at com.opensymphony.xwork2.util.finder.UrlSet.<init>(UrlSet.java:45)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildUrlSet(PackageBasedActionConfigBuilder.java:380)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:352)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:317)
        at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
        at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:204)
        at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)
        at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:374)
        at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:418)
        at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
        at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
        at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
        at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
        at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
        at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4570)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5180)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:697)
        at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1134)
        at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1780)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)
10-Feb-2014 13:13:53.567 SEVERE [localhost-startStop-1] com.opensymphony.xwork2.util.logging.commons.CommonsLogger.error Unable to scan named packages
 java.lang.NullPointerException
        at com.opensymphony.xwork2.util.finder.UrlSet.includeClassesUrl(UrlSet.java:173)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildUrlSet(PackageBasedActionConfigBuilder.java:406)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.findActions(PackageBasedActionConfigBuilder.java:352)
        at org.apache.struts2.convention.PackageBasedActionConfigBuilder.buildActionConfigs(PackageBasedActionConfigBuilder.java:317)
        at org.apache.struts2.convention.ClasspathPackageProvider.loadPackages(ClasspathPackageProvider.java:53)
        at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:204)
        at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)
        at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:374)
        at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:418)
        at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:69)
        at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
        at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
        at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
        at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
        at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4570)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5180)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:697)
        at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1134)
        at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1780)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:744)