It’s these two gems, specifically. I can build them on my local machine, and nix copy them to the server, but building them directly on the server always fails with curl: (6) Could not resolve host: rubygems.org.
(If you want to replicate it: nix build https://codeberg.org/libewa/pages/archive/main.tar.gz.)
Idk…
Maybe you can use a VPN that acts a public ipv4 address so you can get to ipv4 only stuff reliably?
or you can use one of the public free 6to4 gateways?