Hello,

I have been working on an app that uses Req to access a REST API at an AAAA domain record. The domain record is resolvable globally, and also present in /etc/hosts. Everything had been working correctly.

A week ago I reinstalled everything due to an SSD failure. I still use the same versions of Elixir and Erlang installed with asdf:

elixir          1.18.2-otp-27
erlang          27.2.2

The dependencies of my project in mix.exs have not changed.

However, I now get this:

** (MatchError) no match of right hand side value: {:error, %Req.TransportError{reason: :nxdomain}}

Why would Req suddenly stop resolving the AAAA domain record? Has anyone seen this happen? Any ideas what I can do to fix this?

Edit: I can resolve the domain just fine with dig AAAA, and ping it. Also, If I hardcode the IPv6 in the URL of the REST API used by Req, it works – so it’s clear that it’s not an issue caused by IPv6 connectivity, but by AAAA domain resolution.