The rss-glx ebuild contains a hardcoded path to /usr/lib/misc/xscreensaver. Since /usr/lib is a symlink to /usr/lib64, the files get installed to the correct location, but tools such as revdep-rebuild cannot figure out that paths such as "/usr/lib64/misc/xscreensaver/hyperspace" belong to this package. Attached (trivial) patch resolves the issue.
Created attachment 152803 [details, diff] Replace hardcoded "lib" with a call to get_libdir
thanks, fixed in -r5.