$ git clone -n https://src.fedoraproject.org/rpms/nautilus.git /var/lib/mock/f39-build-1626428-39282/root/chroot_tmpdir/scmroot/nautilus
Cloning into '/var/lib/mock/f39-build-1626428-39282/root/chroot_tmpdir/scmroot/nautilus'...
$ git fetch origin 5141d32d0f92041fe17a03010d5ecee0a0cf17a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nautilus
 * [new ref]         5141d32d0f92041fe17a03010d5ecee0a0cf17a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5141d32 Update to 45.1