$ git clone -n https://src.fedoraproject.org/rpms/opam.git /var/lib/mock/f40-build-740186-109556/root/chroot_tmpdir/scmroot/opam
Cloning into '/var/lib/mock/f40-build-740186-109556/root/chroot_tmpdir/scmroot/opam'...
$ git fetch origin 916a01438e7b2dda643524a1215b7cb74a10c0c5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/opam
 * [new ref]         916a01438e7b2dda643524a1215b7cb74a10c0c5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 916a014 OCaml 5.1 rebuild for Fedora 40