NixOS 26.05 – Feature Freeze & Release Blockers

[yayayayaka]

Hi, we are @yayayayaka and @jopejoe1, the release managers for NixOS 26.05 ("Yarara").

We are happy to announce the kickoff of the release schedule! So, it is time to discuss the feature freeze. We want to ensure that this release is as stable and reliable as possible and your contributions are crucial to achieving that goal. Here are the two upcoming dates in that context:

• 2026-04-13 Restrict breaking changes to Release Critical Packages
• 2026-04-27 Restrict all breaking changes

The first restriction will be in place quite soon, therefore, we encourage all teams to check in now and mention possible blockers, so we get a good overview of what's ahead.

Whether you were pinged or not, we encourage everyone to create issues for release blockers and add them to the 26.05 Blockers project.

Check-in

Please comment your status quo and possible issues as soon as possible. We'll check teams once they have checked in.

If you think some subsystem, person or team should be added or removed from this list, update maintainers/team-list.nix in time before the next feature freeze announcement.

Core

• Module system: @infinisil @roberth
• stdenv: @NixOS/stdenv
• systemd: @NixOS/systemd
• NixOS tests: @tfc

Compilers, build systems

• Android: @NixOS/android @JohnRTitor
• Bazel: @mboes @avdv @olebedev @groodt @aherrmann @ylecornec @boltzmannrain
• LLVM: @NixOS/llvm
• loongarch64: @NixOS/loongarch64

Desktop Environments

• Cinnamon: @bobby285271 @mkg20001
• COSMIC: @NixOS/cosmic
• Enlightenment: @NixOS/enlightenment
• GNOME: @NixOS/gnome
• hyprland: @NixOS/hyprland @JohnRTitor
• Lomiri: @OPNA2608
• Lumina: @NixOS/lumina
• LXQt: @NixOS/lxqt
• MATE: @bobby285271 @romildo
• Pantheon: @NixOS/pantheon
• Qt-KDE: @NixOS/qt-kde
• Xfce: @bobby285271 @romildo @muscaln

Languages Ecosystem

• Beam: @NixOS/beam
• C: @Mic92
• Coq: @CohenCyril @Zimmi48 @siraben @vbgl @Alizter @stepbrobd
• CUDA: @NixOS/cuda-maintainers
• Dhall: @Gabriella439
• golang: @NixOS/golang
• Haskell: @NixOS/haskell
• Java: @NixOS/java
• lisp: @NixOS/lisp
• lua: @NixOS/lua
• nim: @NixOS/nim
• Node.js: @winterqt
• OCaml: @NixOS/ocaml
• Perl: @stigtsp @marcusramberg
• php: @NixOS/php
• Python: @mweinelt @natsukium
• R: @b-rodrigues @bcdarwin @jamespeapen @jbedo @Kupac
• rust: @NixOS/rust
• SDL: @NixOS/sdl @evysgarden
• Zig: @RossComputerGuy

Lix & Nix packaging

• Lix maintainers: @NixOS/lix-maintainers
• Nix packaging: @Artturin @Ericson2314 @lovesegfault @Mic92 @philiptaron @roberth @tomberek @xokdvium
• nixos-rebuild: @thiagokokada

Platforms

• darwin-core: @NixOS/darwin-core

Programs

• ACME: @aanderse @arianvp @emilazy @m1cr0man
• electron: @TomaSajt @yayayayaka @teutat3s
• Geospatial: @NixOS/geospatial
• Nextcloud: @bachp @britter @dotlambda @Ma27 @provokateurin
• postgres: @NixOS/postgres
• Xen Project: @NixOS/xen-project

Everyone else:

• Documentation Team: @NixOS/documentation-team
• Marketing Team: @NixOS/marketing-team
• @NixOS/nixpkgs-committers, @NixOS/nixos-release-managers

[yayayayaka]

More maintainer pings:

• Nextcloud: @bachp @britter @dotlambda @Ma27 @provokateurin
• electron: @teutat3s

[xokdvium]

From the Nix side: we want to bump the nixVersions.stable to 2.34.4 sometime this week to have some time before the first restriction.

[K900]

On the Qt/KDE side, Qt 6.11 is now in staging, which is the biggest change, we'll have another Frameworks and Gear update in mid-April, and Plasma 6.7 will not make it in time (which is fine). I'm also looking at removing a big chunk of KF5 stuff, now that its biggest dependent (Krita) is switched to Qt6.

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/26-05-feature-freeze-release-blockers/76704/1

[RaitoBezarius]

On Lix side: Lix 2.95.1 is out and being stabilized. We plan to deprecate/drop Lix 2.93.0 from the current state to keep 94/95 for 26.05.

[Eveeifyeve]

On the nim side, we currently have a pr that introduces breaking changes to nim like removing subversion aliases nim 1 2.0 and 2.2, packages, invalid patches and updated to the latest version. However there is an issue with using nim_lk from the pr, so it would be best to have some more people trying to reproduce the issue: #496960 (comment).

Link to pr: #496960

[britter]

Still not sure where we will land with #490996. Maintainers of affected packages have been pinged but so far not a lot of progress. I still think #491337 should be merged before 26.05.

[thiagokokada]

nixos-rebuild looks in a good state for this cycle. Lots of bug fixes since it became the default and also some new features.

[thefossguy]

On the COSMIC side: We've had no releases for the past several weeks because upstream is in the process of upgrading libcosmic (basically the entire DE) from iced v0.13 to v0.14 which will take an unspecified amount of time. I would like to get the ISO module merged but there are other blockers, which I don't think will be unblocked before 2026-04-13 so that is not an issue either.

In my personal capacity, if there are any non-security updates after 2026-04-27, I will just let it stay as-is and update once nixos-unstable is open for "breaking changes."

[marcin-serwin]

On the SDL side: The last sdl3 bump went smooth and I'm not aware of any problems that need urgent fixing. There is one PR introducing breaking changes but it can happen after branch-off so no blockers as far as I'm aware.

[adamcstephens]

for BEAM, Erlang 29 will be released in a month or two meaning version 26 will go end of life. Meaning OTP 26 will be removed prior to branch off.

[SuperSandro2000]

I'm also looking at removing a big chunk of KF5 stuff, now that its biggest dependent (Krita) is switched to Qt6.

which is still considered beta https://github.com/KDE/krita/blob/c77025f8658e80a8b00142502e4f99c97d0426af/CMakeLists.txt#L389-L392 and they ask to not ship it, yet. https://github.com/KDE/krita/blob/c77025f8658e80a8b00142502e4f99c97d0426af/CMakeLists.txt#L367-L370

Lets see how that evolves and how stable it will be until Mai.

[Gabriella439]

No blockers for Dhall