Installing app-antivirus/clamav with USE="-static-libs" installs the following file: /usr/lib64/libclamunrar_iface.la This is the only .la file installed by the package because prune_libtool_files deleted the other two libclamav.la and libclamunrar.la. As far as I can see, libclamunrar_iface.la was kept around because of this line: dependency_libs=' /usr/lib64/libclamunrar.la -ldl' The actual problem is that when I scan my system for broken libraries, libclamunrar_iface.la triggers a rebuild due to the missing libclamunrar.la listed on the dependency_libs line. I am working around this bug by pasing "--all" to prune_libtool_libs in my personal overlay.
Fixed in 0.97.6.