$ git clone -n https://github.com/xcp-ng-rpms/samba.git /var/lib/mock/v8.3-u-pcoval1-11120-29540/root/chroot_tmpdir/scmroot/samba
Cloning into '/var/lib/mock/v8.3-u-pcoval1-11120-29540/root/chroot_tmpdir/scmroot/samba'...
$ git fetch origin 9a66be8c37ca5c0415e7d6828704429eeb251b8e:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/samba
 * [new ref]         9a66be8c37ca5c0415e7d6828704429eeb251b8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9a66be8 bump release for test build