I get this on basic suite from a built RPM[1]:

Caused by: java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils
	at org.ovirt.vdsm.jsonrpc.client.reactors.stomp.impl.Message.withCorrelationId(Message.java:75) [vdsm-jsonrpc-java-client.jar:]
	at org.ovirt.vdsm.jsonrpc.client.reactors.stomp.SSLStompClient.sendMessage(SSLStompClient.java:85) [vdsm-jsonrpc-java-client.jar:]
	at org.ovirt.vdsm.jsonrpc.client.JsonRpcClient.call(JsonRpcClient.java:83) [vdsm-jsonrpc-java-client.jar:]

My patch under test certainly didn't touch this area [2]

[1] http://jenkins.ovirt.org/job/ovirt-system-tests_manual/290/artifact/exported-artifacts/test_logs/basic-suite-master/post-002_bootstrap.py/lago-basic-suite-master-engine/_var_log/ovirt-engine/engine.log

[2] https://gerrit.ovirt.org/#/c/75262/