mirrorselect presently set the SYNC variable in make.conf when used with the -r/--rsync switch, but that variable is now deprecated. Sources: - https://wiki.gentoo.org/wiki/Mirrorselect - https://wiki.gentoo.org/wiki/SYNC Mirrorselect should instead set the sync-uri variable in repos.conf.
This is in vcs: http://git.overlays.gentoo.org/gitweb/?p=proj/mirrorselect.git;a=commit;h=ae600d2d704209985cc50b914ab47982a842d87b
Released as mirrorselect-2.2.1.