The knowledgeBase plasmoid needs the ocs dataengine in order to get information.
If someone install kdeplasma-addons without the attica use flag then the ocs dataengine will not be installed.
You can check it if you go to,/usr/share/kde4/services/plasma-dataengine-ocs.desktop is missing.So the dataengine isn't installed.
In my diff i removed the attica use flag,and i added libattica as a necessary dependecy.
thanks in advance
Created attachment 293099 [details, diff]
Disagree to transform a optional build dependency to a hard dependency. Maybe the flag should be default enabled, but this have to be discussed.
Fixed, now the knowledgebase plasmoid is only built with USE=attica.