$ git clone -n https://github.com/xcp-ng-rpms/ocaml /var/lib/mock/v9.0-u-ydi1-11045-29480/root/chroot_tmpdir/scmroot/ocaml
Cloning into '/var/lib/mock/v9.0-u-ydi1-11045-29480/root/chroot_tmpdir/scmroot/ocaml'...
$ git fetch origin 90ca647ef1d42219979b8d880b3a55b8fcc4a5d8:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/ocaml
 * [new ref]         90ca647ef1d42219979b8d880b3a55b8fcc4a5d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 90ca647 bump release for test build