Set sync-depth and clone-depth to 1 by default.

[crocket]

I haven't needed to keep the git commit history of overlays.

Thus, I manually write overlays in /etc/portage/repos.conf/overlays.conf instead of using eselect-repository.

/etc/portage/repos.conf/overlays.conf

[crocket-overlay]
location = /var/db/repos/crocket-overlay
sync-type = git
sync-uri = https://github.com/crocket/crocket-overlay.git
clone-depth = 1
sync-depth = 1

[guru]
location = /var/db/repos/guru
sync-type = git
sync-uri = https://anongit.gentoo.org/git/repo/proj/guru.git
clone-depth = 1
sync-depth = 1