$ git clone -n https://github.com/xcp-ng-rpms/xapi /var/lib/mock/v8.3-u-psafont2-10248-28825/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-psafont2-10248-28825/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 8c2409815846e79932566bc2fa2c9fb987007d2e:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         8c2409815846e79932566bc2fa2c9fb987007d2e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8c24098 bump release for test build