$ git clone -n https://src.fedoraproject.org/rpms/nautilus.git /var/lib/mock/f39-build-1953112-43225/root/chroot_tmpdir/scmroot/nautilus
Cloning into '/var/lib/mock/f39-build-1953112-43225/root/chroot_tmpdir/scmroot/nautilus'...
$ git fetch origin f465633dea6c12ebf381ab4248e1db3fd9c7e0ec:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nautilus
 * [new ref]         f465633dea6c12ebf381ab4248e1db3fd9c7e0ec -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f465633 Update to 45.2.1