$ git clone -n https://src.fedoraproject.org/rpms/opam.git /var/lib/mock/f41-build-821281-152509/root/chroot_tmpdir/scmroot/opam
Cloning into '/var/lib/mock/f41-build-821281-152509/root/chroot_tmpdir/scmroot/opam'...
$ git fetch origin f56834e3512ffb65743a9f55348229673e3d2861:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/opam
 * [new ref]         f56834e3512ffb65743a9f55348229673e3d2861 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f56834e Version 2.2.0