$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo.git /var/lib/mock/v8.3-incoming-10896-29365/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v8.3-incoming-10896-29365/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin 7a4e5d647f79ca1a5830d900ffc482fd4a598072:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         7a4e5d647f79ca1a5830d900ffc482fd4a598072 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7a4e5d6 Merge pull request #15 from xcp-ng-rpms/asv/lcm-sparse-vhd-qcow