$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo.git /var/lib/mock/v8.3-incoming-11488-29780/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v8.3-incoming-11488-29780/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin 9ffc5b70be8e718976a4ca87a6bd668c165251b9:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         9ffc5b70be8e718976a4ca87a6bd668c165251b9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9ffc5b7 Merge pull request #17 from xcp-ng-rpms/asv/fix-snap-export-qcow2