$ git clone -n https://src.fedoraproject.org/rpms/coin-or-Ipopt.git /var/lib/mock/f42-build-864962-172682/root/chroot_tmpdir/scmroot/coin-or-Ipopt
Cloning into '/var/lib/mock/f42-build-864962-172682/root/chroot_tmpdir/scmroot/coin-or-Ipopt'...
$ git fetch origin 89746e7d9ca50a1cd56f01c4089215b6d1418719:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/coin-or-Ipopt
 * [new ref]         89746e7d9ca50a1cd56f01c4089215b6d1418719 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 89746e7 Rebuild for MUMPS-5.7.3