With Avahi bug #311, I understand it was agreed the bug was on Lennart to fix.
Still, I would just like to reiterate that in 2013 on some misconfigured public hotspots the avahi-daemon-check-dns.sh indeed doesn't stop the daemon, which makes the hotel hotspot unavailable to the unaware travelling novice. For the particular server I have in mind, no DNS records exist for domain 'local': $ nslookup > server Default server: 10.5.50.1 Address: 10.5.50.1#53 > > hotspot.plaza.local Server: 10.5.50.1 Address: 10.5.50.1#53 Non-authoritative answer: Name: hotspot.plaza.local Address: 10.5.50.1 > > plaza.local Server: 10.5.50.1 Address: 10.5.50.1#53 Non-authoritative answer: Name: plaza.local Address: 192.168.120.97 Name: plaza.local Address: 192.168.120.99 > > local Server: 10.5.50.1 Address: 10.5.50.1#53 ** server can't find local: SERVFAIL > > And /etc/resolv.conf holds: $ cat /etc/resolv.conf domain hotspot.plaza search hotspot.plaza OS X indeed has no trouble connecting.