For example $ equery belongs `which msgfmt` * Searching for /afs/mrph.org/sys/gentoo/amd64_linux26/usr/bin/msgfmt ... !!! Invalid CPV: 'app-arch/xz-utils-4.999.9_beta-r00.1' This happens regardless of what file you pass to equery belongs.
The alternative is qfile from portage-utils. %% qfile `which msgfmt` sys-devel/gettext (/usr/bin/msgfmt) *** This bug has been marked as a duplicate of bug 313295 ***