$ git clone -n https://src.fedoraproject.org/rpms/ocaml-tyxml.git /var/lib/mock/f40-build-784153-133252/root/chroot_tmpdir/scmroot/ocaml-tyxml
Cloning into '/var/lib/mock/f40-build-784153-133252/root/chroot_tmpdir/scmroot/ocaml-tyxml'...
$ git fetch origin ab92b78edc333f86ff729d66f83002cada286140:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-tyxml
 * [new ref]         ab92b78edc333f86ff729d66f83002cada286140 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ab92b78 Rebuild for changed ocamlx(Location) hash