$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo /var/lib/mock/v9.0-incoming-11618-29897/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v9.0-incoming-11618-29897/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin a82624e8d82bf0e4f671c4780baab2c09ec9d837:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         a82624e8d82bf0e4f671c4780baab2c09ec9d837 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a82624e Merge pull request #16 from xcp-ng-rpms/ydi/9