Drewry Pope (Nov 02 2025 at 21:04): Drewry Pope (Nov 02 2025 at 21:04):hi roc friends, i looked at the couple previous nix flake topics but i think this is newer..
is there an updated flake somewhere with an in-support rust version OR a zig-only version?
i'm all good with nightly builds, closer to master the better, preferably with a flake to depend on. is this possible right now? should i make some sort of hashed binary derivation instead?
Drewry Pope (Nov 02 2025 at 21:06):(1.77.2 is eol i think, by default i try to run just a single nixpkgs when possible. i could go ahead and use the roc flake as-is without following my nixpkgs from 2025, but wanted to check first. maybe it's better if i don't rely on this flake for now, add my own derivation directly in my repo?)
Anton (Nov 04 2025 at 09:29):Hi @Drewry Pope,
is there an updated flake somewhere with an in-support rust version
No, I have not updated the rust version so I can focus on getting the new compiler ready.
OR a zig-only version?
Yes: https://github.com/roc-lang/roc/blob/main/src/flake.nix. But, it is not ready to replace the old compiler yet.
Anton (Nov 04 2025 at 09:29):i could go ahead and use the roc flake as-is without following my nixpkgs from 2025
That would be the approach I recommend.
Hannes (Nov 05 2025 at 01:41):I noticed that the flake for the new Zig compiler doesn't define any output packages, is there a technical reason for that or is it just a lower priority thing?
Anton (Nov 05 2025 at 08:36):Yeah, lower priority
Hannes (Nov 05 2025 at 09:12):Cool, because that means I can open a PR for my local branch where I've added it :sweat_smile:
Hannes (Nov 05 2025 at 10:27):It's open here: https://github.com/roc-lang/roc/pull/8351
Anton (Nov 05 2025 at 11:57):Thanks, I'll check it out :)
Anton (Nov 05 2025 at 12:17):Hmm, this is going very slowly for me:
❯ nix run ./src/#roc
warning: Git tree '/Users/username/gitrepos/forks/hasnep/roc' is dirty
[1/0/1 built] building roc (buildPhase): install -C .zig-cache/o/63519b81310eced5835dbe3ca5ae69cd/roc /nix/var/nix/builds/nix-9378-2989836767/5lsb292nlfn65p09g6aqlfz2bdbsq44h-source/zig-out/bin/roc
But when I look in activity monitor it's not using much CPU or memory at all
Georges Boris (Jan 26 2026 at 13:38):Hey folks - anyone using the new compiler with nix flakes?
I noticed there is an open PR but seems inactive.
IIRC Anton used nix flakes for roc development, right? Do you have any working setup available?
Rick Hull (Jan 26 2026 at 13:42):Georges, i used to run nixos and I used to do nix flake for some project setup, but I abandoned this approach for a moment. So i may be able to help a little, maybe not. But have you seen https://github.com/rickhull/roc-init ?
Anton (Jan 26 2026 at 13:51):Georges Boris said:
Hey folks - anyone using the new compiler with nix flakes?
I noticed there is an open PR but seems inactive.IIRC Anton used nix flakes for roc development, right? Do you have any working setup available?
Hi Georges :) we already have a new compiler flake, use it with 'nix develop ./src'
Hannes (Jan 26 2026 at 13:55):Georges Boris said:
I noticed there is an open PR but seems inactive.
That PR will become active again next week when I quit my job and have more time to work on Roc again :sweat_smile:
Rick Hull (Jan 26 2026 at 13:56):https://github.com/roc-lang/roc/blob/main/src/flake.nix # cool
Eli Dowling (Jan 26 2026 at 14:52):Oh and you should know that it seems like you need to run tests from the top level '/'. So I always run nix develop from in /src then go back to / and run zig build test
Hannes (Jan 26 2026 at 23:56):You should be able to run nix develop ./src to use the flake in the src directory
Last updated: Feb 20 2026 at 12:27 UTC