$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois1-9576-28324/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois1-9576-28324/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 9e9b8a10d59a710161578b59270494d521fc25fb:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         9e9b8a10d59a710161578b59270494d521fc25fb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9e9b8a1 bump release for test build