NPE in Weld when a portable extension is added by JBoss AS deployer

I am getting a NPE in Weld when I try to add a portable extension to an application using PathUrlIntegrationDeployer. (See stacktrace.txt for details) Note that everything works OK when the portable extension is bundled physically with the application.

To reproduce:
1) Take a fresh JBoss AS 6 M2
2) Remove RESTEasy deployer (rm -r ${JBOSS_HOME}/server/default/deployers/resteasy-deployer)
3) Replace the old RESTEasy deployer with a new one (unzip resteasy-int-all.zip -d ${JBOSS_HOME}/server/default/deployers)
4) Start the AS in default configuration
5) Deploy the testing application (cp resteasy-cdi.war ${JBOSS_HOME}/server/default/deploy)