I would say most definitely related to the classloading issue. Only one TestRunner is allowed per classloader.
The D:/tmp/arquillian-apache-tomee/apache-tomee-plus-1.0.0-beta-2/temp/arquillian-junit-4211441189472437588.jar is going to be on the application root classloader and all child classloaders will see it, so the C:/cygwin/tmp/2/test/WEB-INF/lib/arquillian-junit.jar should not be there and needs to be excluded - Or the other way round? This has something to do with the old classloader jar file locking issue on Windows (which copies jars to the temp dir), so this is only ever going to pop up on a windows machine. -- View this message in context: http://openejb.979440.n4.nabble.com/VOTE-OpenEJB-4-0-0-beta-2-TomEE-1-0-0-beta-2-tp4274468p4285131.html Sent from the OpenEJB Dev mailing list archive at Nabble.com.