$ git clone -n https://src.fedoraproject.org/rpms/ocaml-jane-street-headers.git /var/lib/mock/f42-build-865516-173241/root/chroot_tmpdir/scmroot/ocaml-jane-street-headers
Cloning into '/var/lib/mock/f42-build-865516-173241/root/chroot_tmpdir/scmroot/ocaml-jane-street-headers'...
$ git fetch origin f4a97edf392307b24bf496c638303993447ba8ce:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-jane-street-headers
 * [new ref]         f4a97edf392307b24bf496c638303993447ba8ce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f4a97ed OCaml 5.3.0 rebuild for Fedora 42