app-doc/kchmviewer-3.1_p2 needs kdelibs-3 to compile when USE="kde" is set. If only kdelibs-4 is installed, it will fail to build Reproducible: Always Steps to Reproduce: 1. emerge =kde-base/kdelibs:kde-4 2. emerge kchmviever Actual Results: checking for kde-config... not found configure: error: The important program kde-config was not found! Please check whether you installed KDE correctly. Expected Results: depend on the correct version of kdelibs changing the dependency to kde-base/kdelibs:3.5 should fix the issue.