ring-trace breaks when whois.cymru.com is down

[rodecker]

$ ring-trace -n 2 ring.nlnog.net
ring-trace v1.8.1 - written by Teun Vink teun@teun.tv
picked 2 hosts at random: voxel02 claranet06
Performing ICMP traceroutes towards ring.nlnog.net from 2 ring hosts, ssh-timeout is 10 seconds.
Failed to lookup ASNs at cymru.com.
Traceback (most recent call last):
File "/usr/local/bin/ring-trace", line 1453, in
ns.show_country, ns.remove_broken, ns.highlight_ixp, ns.remove_duplicate, ns.transparent)
File "/usr/local/bin/ring-trace", line 825, in graph
"\n%s" % tracedata[ips[index]]['fqdn'] if (index == 0 or resolve) else "",
KeyError: 'fqdn'
$