Created attachment 224347 [details]
If /etc/resolv.conf has a link-local IPv6 address for the DNS server, then host does not function even though ping works properly. I have traced the problem to /usr/src/contrib/unbound/libunbound/libunbound.c where the test for valid characters does not accept the % or some of the following characters.
I have attached a patch which I believe resolves the problem, but am unable to test it in the system as I was not able to figure out how to build host with the updated file. I am also not confident that there are other places that use that lib that cannot handle the link-local addresses.
Created attachment 224348 [details]
Reversed Patch file