The problem seems to be the Nix 2.0 release, as newer versions of nixpkgs require it, and 17.09 still has a Nix 1.x. Also for some reason mapAttrs is missing

Let's take a detour through 18.03 instead! Which ships Nix 2.x but also evaluates correctly with Nix 1.x, it seems

Also, even a remote deployment via morph didn't work on this system, because the protocol underlying nix-copy-closure has changed enough that my local copy of Nix was incompatible with the one on the other system

Another detour through 19.09 because of a Nix >= 2.2 requirement...

lmfao it ran out of memory while evaluating, because of course it did

What the hell, the upgrade to 19.09 succeeded but turned off my swapfile in the process??

Also I am basically playing a game of "how many soft-deprecated option warnings can I collect before Nix decides that it's had enough and I must fix these options *right now*"

Another detour through 21.11. Can I install 24.11 now?

Nope!

Well, through 23.05 we go.

For some reason, I feel like this upgrade process could be improved. #NixOS

We have made it to 24.11, that's 7 years worth of #NixOS releases! Albeit with a detour through 4 intermediate releases.

It's about the journey, not the destination?

The system still boots fine, too!

I do have to say, I'm not impressed with Nix using an assert to check protocol compatibility for nix-copy-closure, leading to it just coredumping without a useful error message if you try to copy to a too-old #NixOS installation...

Success!

Alright, I should now have daily automated client-encrypted backups of all* my servers to two locations, one in the US and one in the Netherlands.

* except the 'workbot' server, which is a dedicated server that only handles high-resource workloads on ephemeral bulk data, like the seekseek crawler backend, and is not allowed to contain any critical data to begin with

@joepie91 wait, the proper way to keep my Nix updated is not to leave those warnings be warnings until they've become hard errors?