Created attachment 151978 [details]
Proyect with the smallest possible test case

According to Jsf 2.2 specification, you can add composite components to your taglibs, but Netbeans complains about not found the component, and when you run the web app it works well.

With an example provided from https://jsflive.wordpress.com/2013/04/06/jsf22-cc-taglib/ i created and added a composite component to my taglib:
(test.taglib) With 2 components, one composite:

    <tag>
        <tag-name>decorated</tag-name>
        <source>ui/decorated.xhtml</source>
    </tag>
    <tag>
        <tag-name>compositeTest</tag-name>
        <component>
            <resource-id>ui/compositeTest.xhtml</resource-id>
        </component>
    </tag>

Then when i try to use in a view the autocomplete can get me the decorated component, but netbeans complains about "The component library http://test.org/jsf/ui does not contain component compositeTest", if you ignore the error and run the app the everything work as spected.
Attached a simple test case created with NB 8.0.2 and Glassfish tested in ubuntu, you can see how the editor mark an error but if you run the app the two components are rendered fine.