$ git clone -n https://github.com/xcp-ng-rpms/xapi.git /var/lib/mock/v8.3-u-abourgeois1-9617-28353/root/chroot_tmpdir/scmroot/xapi
Cloning into '/var/lib/mock/v8.3-u-abourgeois1-9617-28353/root/chroot_tmpdir/scmroot/xapi'...
$ git fetch origin 4a0e6a100e3cf3e989e1d47c88ced8c3f40a5a63:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xapi
 * [new ref]         4a0e6a100e3cf3e989e1d47c88ced8c3f40a5a63 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a0e6a1 bump release for test build