Apparently ever since https://admin.fedoraproject.org/updates/FEDORA-2015-2020/file-5.22-2.fc21 landed in f21 buildroot, rpm-build no longer generates -devel library symlink dependencies. For example, this build had file--5.19-7.fc21 in the buildroot, kde-workspace-devel-4.11.15-3.fc21.i686.rpm: https://koji.fedoraproject.org/koji/rpminfo?rpmID=5889491 includes a dependency on libkdecorations.so.4 (among other libraries). A more recent build with file-5.22-2.fc21 in the buildroot, kde-workspace-devel-4.11.16-4.fc21.i686.rpm: https://koji.fedoraproject.org/koji/rpminfo?rpmID=6070745 lacks all such dependencies. I verified doing a scratch build of 4.11.16-4 with f21 GA file-5.19-7.fc21 in the buildroot, the dependencies appear as expected
*** This bug has been marked as a duplicate of bug 1207945 ***