$ git clone -n https://src.fedoraproject.org/rpms/nautilus.git /var/lib/mock/f40-build-803451-144267/root/chroot_tmpdir/scmroot/nautilus
Cloning into '/var/lib/mock/f40-build-803451-144267/root/chroot_tmpdir/scmroot/nautilus'...
$ git fetch origin 7f78c1097126c8e09b06446ee0d1f7cd31c64589:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nautilus
 * [new ref]         7f78c1097126c8e09b06446ee0d1f7cd31c64589 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7f78c10 Update to 46.0