$ git clone -n https://github.com/xcp-ng-rpms/xs-opam-repo /var/lib/mock/v9.0-u-ydi1-11213-29594/root/chroot_tmpdir/scmroot/xs-opam-repo
Cloning into '/var/lib/mock/v9.0-u-ydi1-11213-29594/root/chroot_tmpdir/scmroot/xs-opam-repo'...
$ git fetch origin 631fd3a7368d151b46828806ab5e92200b69d012:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/xs-opam-repo
 * [new ref]         631fd3a7368d151b46828806ab5e92200b69d012 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 631fd3a bump release for test build