$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo /var/lib/mock/v9.0-u-ydi1-11234-29600/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v9.0-u-ydi1-11234-29600/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin aeb404516fac30746c9430171f21330bbce62998:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         aeb404516fac30746c9430171f21330bbce62998 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aeb4045 bump release for test build