This Week in NixOS, Week 32 2025
Aug 10, 2025I often send to friends links about the NixOS ecosystem that I find interesting. I figured it's better if I write about it so I have an easily accessible archive of these links. Keep in mind, these links are based on my personal preferences and my observations.
While the name is a reference to This Week in Matrix, this won't necessarily be a weekly occurence. In the past, there were two different efforts to provide a weekly NixOS newsletter. The first was the official NixOS Weekly, that was published on and off for a few years. The GitHub repository was archived and there was a discussion about attempts at reviving the newsletter. The second was nixpkgs.news which has 21 entries covering from February until the beginning of July 2024.
Conferences
Nix Vegas during Defcon
This weekend (7-10 August) Defcon 33 is taking place in Las Vegas and so is Nix Vegas as part of it! Check out the schedule and also take a look at the repository powering the local builders and cache they setup for the event.
I only managed to catch a few talks during the second day on the livestream, but
the recordings should be available in the Defcon Youtube account later on. I
look forward to watching some of the ones I missed. It was fun and a good
learning experience seeing people review nixpkgs PRs on the livestream during
one of the Maybe A Few Hydra Failures sessions.
Nixcon 2025
NixCon 2025 will take place between the 5th and 7th of September in Switzerland and the schedule for it is now published. There's lots of interesting talks in there. I'll be attending NixCon and I'll also be presenting on the second day, so I'm looking forward to this event!
Customized NixOS name plates are available to buy until the 20th of August, so if you want some beautiful NixOS merch get it while it's still available. It's only possible to pick these up in NixCon.
Infrastructure
S3 Binary cache size
@hexa shared some numbers about the NixOS binary cache size. Turns out the cache is currently 705 Terabytes and growing at a rate of ~280 GB per day. About 100 of those TB are in S3 Infrequent Access storage class.
Signing packages with multiple keys (RFC 0149)
@picnoir opened a PR with a proof of concept for signing binary packages in the staging Hydra using multiple keys! This is a step forward to finally changing the old signing key of Hydra. It's currently blocked on the upcoming Hydra security advisory that's scheduled for the 12th of August.
Nixpkgs
Modular services
@roberth created a meta issue for tracking modular services. I haven't read or understood all of the details of it yet, but it aligns with RFC 0189 which is something that I think is currently missing from the way services are defined in NixOS.
Documentation for commit prefixes
@doronbehar documented on nixpkgs the automatic builds that happen on OfBorg based on commit prefixes. This is mentioned on the OfBorg README, but it makes more sense to have it as part of nixpkgs as well. It's something that tripped me up too when I first contributed to nixpkgs.
Source: GitHub
Comments on Fediverse.
