You can see the exception here:

-------------------------------------------------------------------------------
Test set: org.jboss.seam.exception.control.test.extension.ExtensionErrorTest
-------------------------------------------------------------------------------
Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.711 sec <<< FAILURE!
org.jboss.seam.exception.control.test.extension.ExtensionErrorTest Time elapsed: 0 sec <<< ERROR!
org.jboss.arquillian.container.spi.client.container.DeploymentException: Could not deploy to container
at org.jboss.as.arquillian.container.ArchiveDeployer.deploy(ArchiveDeployer.java:58)
at org.jboss.as.arquillian.container.CommonDeployableContainer.deploy(CommonDeployableContainer.java:111)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController$3.call(ContainerDeployController.java:148)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController$3.call(ContainerDeployController.java:115)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController.executeOperation(ContainerDeployController.java:246)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController.deploy(ContainerDeployController.java:114)
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.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.container.impl.client.ContainerDeploymentContextHandler.createDeploymentContext(ContainerDeploymentContextHandler.java:78)
at sun.reflect.GeneratedMethodAccessor7.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.container.impl.client.ContainerDeploymentContextHandler.createContainerContext(ContainerDeploymentContextHandler.java:57)
at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.container.impl.client.container.DeploymentExceptionHandler.verifyExpectedExceptionDuringDeploy(DeploymentExceptionHandler.java:50)
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.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:134)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:114)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController$1.perform(ContainerDeployController.java:86)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController$1.perform(ContainerDeployController.java:79)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController.forEachDeployment(ContainerDeployController.java:238)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController.forEachManagedDeployment(ContainerDeployController.java:222)
at org.jboss.arquillian.container.impl.client.container.ContainerDeployController.deployManaged(ContainerDeployController.java:78)
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.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:134)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:114)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.container.test.impl.client.ContainerEventController.execute(ContainerEventController.java:97)
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.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:68)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:54)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:90)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:134)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:114)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.beforeClass(EventTestRunnerAdaptor.java:80)
at org.jboss.arquillian.junit.Arquillian$2.evaluate(Arquillian.java:158)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:290)
at org.jboss.arquillian.junit.Arquillian.access$100(Arquillian.java:45)
at org.jboss.arquillian.junit.Arquillian$3.evaluate(Arquillian.java:175)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.jboss.arquillian.junit.Arquillian.run(Arquillian.java:123)
at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:59)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:120)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:103)
at org.apache.maven.surefire.Surefire.run(Surefire.java:169)
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.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:350)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)
Caused by: java.lang.Exception: {
"Failed services" =>

{"jboss.deployment.unit.\"extensionError.war\".WeldService" => "org.jboss.msc.service.StartException in service jboss.deployment.unit.\"extensionError.war\".WeldService: org.jboss.weld.exceptions.DefinitionException: Exception List with 1 exceptions: Exception 0 : java.lang.IllegalArgumentException: Handler method public void org.jboss.seam.exception.control.test.handler.HandlerWhichThrowsExceptions.throwsAnException(org.jboss.seam.exception.control.CaughtException) throws java.lang.Exception must not throw exceptions at org.jboss.seam.exception.control.extension.CatchExtension.findHandlers(CatchExtension.java:93) at sun.reflect.GeneratedMethodAccessor413.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.weld.util.reflection.SecureReflections$13.work(SecureReflections.java:305) at org.jboss.weld.util.reflection.SecureReflectionAccess.run(SecureReflectionAccess.java:54) at org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInvocation(SecureReflectionAccess.java:163) at org.jboss.weld.util.reflection.SecureReflections.invoke(SecureReflections.java:299) at org.jboss.weld.introspector.jlr.WeldMethodImpl.invokeOnInstance(WeldMethodImpl.java:188) at org.jboss.weld.introspector.ForwardingWeldMethod.invokeOnInstance(ForwardingWeldMethod.java:59) at org.jboss.weld.injection.MethodInjectionPoint.invokeOnInstanceWithSpecialValue(MethodInjectionPoint.java:198) at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:282) at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:265) at org.jboss.weld.event.ObserverMethodImpl.notify(ObserverMethodImpl.java:234) at org.jboss.weld.manager.BeanManagerImpl.notifyObservers(BeanManagerImpl.java:632) at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:619) at org.jboss.weld.bootstrap.events.AbstractContainerEvent.fire(AbstractContainerEvent.java:67) at org.jboss.weld.bootstrap.events.AbstractDefinitionContainerEvent.fire(AbstractDefinitionContainerEvent.java:42) at org.jboss.weld.bootstrap.events.ProcessManagedBeanImpl.fire(ProcessManagedBeanImpl.java:34) at org.jboss.weld.bootstrap.AbstractBeanDeployer.deploy(AbstractBeanDeployer.java:126) at org.jboss.weld.bootstrap.BeanDeployment.deployBeans(BeanDeployment.java:216) at org.jboss.weld.bootstrap.WeldBootstrap.deployBeans(WeldBootstrap.java:370) at org.jboss.as.weld.WeldContainer.start(WeldContainer.java:81) at org.jboss.as.weld.services.WeldService.start(WeldService.java:89) at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1765) at org.jboss.msc.service.ServiceControllerImpl$ClearTCCLTask.run(ServiceControllerImpl.java:2291) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662) "}

,
"Services with missing/unavailable dependencies" => [
"jboss.deployment.unit.\"extensionError.war\".component.\"org.jboss.seam.solder.resourceLoader.servlet.ResourceListener\".WeldInstantiator",
"jboss.deployment.unit.\"extensionError.war\".jndiDependencyService",
"jboss.deployment.unit.\"extensionError.war\".component.\"org.jboss.as.weld.webtier.jsp.JspInitializationListener\".START",
"jboss.web.\"extensionError.war\"",
"jboss.naming.context.java.module.extensionError.extensionError.BeanManager",
"jboss.deployment.unit.\"extensionError.war\".component.\"org.jboss.seam.solder.resourceLoader.servlet.ResourceListener\".START",
"jboss.deployment.unit.\"extensionError.war\".beanmanager",
"jboss.deployment.unit.\"extensionError.war\".component.\"org.jboss.as.weld.webtier.jsp.JspInitializationListener\".WeldInstantiator"
]
}
at org.jboss.as.controller.client.helpers.standalone.impl.ServerDeploymentPlanResultFuture.getActionResult(ServerDeploymentPlanResultFuture.java:99)
at org.jboss.as.controller.client.helpers.standalone.impl.ServerDeploymentPlanResultFuture.getResultFromNode(ServerDeploymentPlanResultFuture.java:88)
at org.jboss.as.controller.client.helpers.standalone.impl.ServerDeploymentPlanResultFuture.get(ServerDeploymentPlanResultFuture.java:70)
at org.jboss.as.controller.client.helpers.standalone.impl.ServerDeploymentPlanResultFuture.get(ServerDeploymentPlanResultFuture.java:42)
at org.jboss.as.arquillian.container.ArchiveDeployer.executeDeploymentPlan(ArchiveDeployer.java:75)
at org.jboss.as.arquillian.container.ArchiveDeployer.deploy(ArchiveDeployer.java:56)
... 88 more

The exception I'm expecting is the DefinitionException, not java.lang.Exception. Understandably it may not be correct to pass back the actual exception without wrapping it, but wrapping in java.lang.Exception doesn't really cut it either.