$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois1-10221-28796/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois1-10221-28796/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 61a8dadd1b786ae4315399de2216ed7ce4974e4a:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         61a8dadd1b786ae4315399de2216ed7ce4974e4a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 61a8dad bump release for test build