aria2 cannot use async DNS, needs netlink

It decides whether to use IPv4 or IPv6 DNS based on your network interface configuration, which is obtained over netlink, and netlink is not implemented. So it fails to get your network interfaces and thus assumes your system is not capable of IPv4 or IPv6, and doesn't even try to do DNS lookups.

Workaround: use `--async-dns=false`.

Start by tracing aria2's async DNS interface-detection path and how it depends on netlink, since the issue names no files or tests. Done means async DNS can determine IPv4 or IPv6 capability and perform DNS lookups without requiring --async-dns=false.

Written by the indexing model from the issue text.