We have an integration test running in a Struts 2 sample application, and after the maven-surefire-plugin was updated from 2.3 to 2.4, the test is failing. There's an issue registered in the Struts 2 JIRA explaining the error: https://issues.apache.org/struts/browse/WW-2494
I have no idea what's causing the error, but I suspect it has something to do witn classloader configuration, as aparently no tld files are found inside the jar files on the classpath.
It should be pretty easy to reproduce. Just checkout the Struts 2 code and run 'mvn test' on the portlet example application.