Perfectus build fails for "JON Plugins :: ActiveMQ Plugin" artifact

[INFO] --- maven-antrun-plugin:1.7:run (default) @ activemq-plugin ---
[INFO] Executing tasks

main:
     [echo] Validating plugin activemq-plugin
     [java] Exception in thread "main" java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;[Ljava/lang/Object;Ljava/lang/Throwable;)V
     [java] 	at org.apache.commons.logging.impl.SLF4JLocationAwareLog.warn(SLF4JLocationAwareLog.java:185)
     [java] 	at org.rhq.core.pc.plugin.PluginValidator.findPluginJars(PluginValidator.java:282)
     [java] 	at org.rhq.core.pc.plugin.PluginValidator.main(PluginValidator.java:80)