localhost doesn't resolve to ::1, despite having the correct entry in /etc/hosts

[treysis]

I cannot connect/ping localhost to resolve to IPv6 ::1 if there is no other IPv6 configured.

I made sure that /etc/hosts reads ::1 localhost, I also made sure that ifconfig shows ::1 for the lo interface. But ping or connect will not resolve, even if I force address family via -A inet6. It only works after I set another IPv6 address.

Why can't I connect to ::1? This also causes problems with the NodeJS testing suite: nodejs/node#37931

Unless I disable IPv6 in kernel, connecting to ::1 or localhost resolving to ::1 should work just fine. It does on Linux and Windows.

[sjorge]

Might be hitting https://www.illumos.org/issues/7494 or a similar issue.
Python still doesn't do the right thing for saltstack to this day.

[treysis]

Turned out this is normal behavior due to calling getaddrinfo() with AI_ADDRCONFIG when doing lookups.