# cat /etc/portage/repos.conf/gentoo.conf [DEFAULT] main-repo = gentoo [gentoo] location = /var/db/repos/gentoo sync-type = git sync-uri = https://github.com/gentoo/gentoo-portage-rsync-mirror.git auto-sync = true ics6web ~ # nano /etc/portage/make.conf ics6web ~ # cat /etc/portage/repos.conf/gentoo.conf [DEFAULT] main-repo = gentoo [gentoo] location = /var/db/repos/gentoo sync-type = git sync-uri = https://github.com/gentoo/gentoo-portage-rsync-mirror.git auto-sync = true ics6web ~ # grep SYNC /etc/portage/make.conf SYNC=rsync://rsync.j-schmitz.net/gentoo-portage ics6web ~ # emerge --sync >>> Synchronization of repository 'gentoo' located in '/var/db/repos/gentoo'... !!! /var/db/repos/gentoo appears to be under revision control (contains .git). !!! Aborting rsync sync. ics6web ~ # ll -d /var/db/repos/gentoo/.git drwxr-xr-x 7 portage portage 4.0K Feb 2 08:19 /var/db/repos/gentoo/.git/ When removing SYNC from make.conf emerge --sync works fine.
OK, I found the override code in portage/repository/config.py. It was a backward compatibility variable for older mirrorselect. Newer mirrorselect modifies repos.conf instead. fixed in commit: https://github.com/gentoo/portage/commit/d88cf4746c0fe891087a79d630e9d8181c7cbd04
Released in portage-2.2.17