$ git clone -n https://src.fedoraproject.org/rpms/R-units.git /var/lib/mock/f39-build-2279954-55362/root/chroot_tmpdir/scmroot/R-units
Cloning into '/var/lib/mock/f39-build-2279954-55362/root/chroot_tmpdir/scmroot/R-units'...
$ git fetch origin 95dc8d17d599d1ee9758319f1b154bf0dd1434d3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-units
 * [new ref]         95dc8d17d599d1ee9758319f1b154bf0dd1434d3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 95dc8d1 Update to 0.8-5