# Changelog: Nix 2.32.5 ## Bug Fixes ### Critical Crashes Fixed - **Fix heap-use-after-free crash under high build load** ([#14772](https://github.com/NixOS/nix/pull/14772)) Fixed a daemon segfault that could occur under high build load. The issue was caused by the `initialOutputs` field referencing data from an activation frame that had gone out of scope during coroutine tail-call optimization in the build scheduler. - **Fix segfault when querying non-existent derivation files** ([#14571](https://github.com/NixOS/nix/issues/14571), [#14572](https://github.com/NixOS/nix/pull/14572)) Running `nix derivation show /nix/store/...-doesnotexist.drv` would crash with a segfault. Now properly returns an "invalid store path" error. - **Fix RestrictedStore::addDependency crash** ([#14729](https://github.com/NixOS/nix/pull/14729)) Fixed a crash caused by incorrect non-virtual interface pattern implementation that led to bad recursion/UB in `addDependencyPrep`. ### Regressions Fixed - **Fix "dynamic attributes not allowed in let" regression** ([#14642](https://github.com/NixOS/nix/issues/14642), [#14646](https://github.com/NixOS/nix/pull/14646)) Expressions like `let a = 1; "b" = 2; ${"c"} = 3; in [ a b c ]` that worked in 2.30 would incorrectly fail in 2.32.x. This was caused by the ExprString arena optimization, which has been reverted. - **Fix fetchGit with `ref = "HEAD"` regression** ([#13948](https://github.com/NixOS/nix/issues/13948), [#14672](https://github.com/NixOS/nix/pull/14672)) `fetchGit { url = "..."; ref = "HEAD"; }` was broken and returned "revspec 'HEAD' not found". - **Fix unnecessary substituter queries** ([#14836](https://github.com/NixOS/nix/issues/14836), [#14837](https://github.com/NixOS/nix/pull/14837)) Fixed a regression where Nix would query all substituters (including `cache.nixos.org`) even when a higher-priority local substituter already had the path. This caused unnecessary network traffic. ### Platform-Specific Fixes - **Fix curl with c-ares failing DNS resolution in macOS sandbox** ([#14792](https://github.com/NixOS/nix/pull/14792)) When curl is built with c-ares (as in recent nixpkgs), DNS resolution would fail inside the Nix build sandbox on macOS with "Could not contact DNS servers". ### Store & File System Fixes - **Fix file system race conditions in store optimization** ([#14676](https://github.com/NixOS/nix/pull/14676), [#7273](https://github.com/NixOS/nix/issues/7273)) Multiple fixes to `optimizePath_`: - Actually call `remove()` when `rename()` fails - Propagate error codes in `createSymlink()` - Make `AutoDelete` non-copyable and non-movable to prevent use-after-free ## Improvements - **Include path in world-writable error messages** ([#14785](https://github.com/NixOS/nix/pull/14785)) The error message for world-writable directory checks now includes the specific path that failed, making debugging easier. - **Documentation: correct `build-dir` error information** ([#14745](https://github.com/NixOS/nix/pull/14745)) Fixed out-of-date information in the manual about `build-dir` errors and added links to relevant settings. ## Maintenance - CI improvements: added `upload-release.yml` workflow, improved Docker push workflow configurability, updated magic-nix-cache with post-build-hook fix - Documented maintainer git tag signing process - Fixed lowdown override compatibility with newer nixpkgs - Removed mdbook-linkcheck and added support for mdbook 0.5.x - Remove static data from headers to fix compilation issues - **Fix heap-use-after-free crash under high build load** ([#14772](https://github.com/NixOS/nix/pull/14772)) --- Diff: https://github.com/NixOS/nix/compare/2.32.4...2.32.5
Nixpkgs is a collection of over 120,000 software packages that can be installed with the Nix package manager. It also implements NixOS, a purely-functional Linux distribution.
Manuals
- NixOS Manual - how to install, configure, and maintain a purely-functional Linux distribution
- Nixpkgs Manual - contributing to Nixpkgs and using programming-language-specific Nix expressions
- Nix Package Manager Manual - how to write Nix expressions (programs), and how to use Nix command line tools
Community
- Discourse Forum
- Matrix Chat
- Official wiki
- Community-maintained list of ways to get in touch (Discord, Telegram, IRC, etc.)
Other Project Repositories
The sources of all official Nix-related projects are in the NixOS organization on GitHub. Here are some of the main ones:
- Nix - the purely functional package manager
- NixOps - the tool to remotely deploy NixOS machines
- nixos-hardware - NixOS profiles to optimize settings for different hardware
- Nix RFCs - the formal process for making substantial changes to the community
- NixOS homepage - the NixOS.org website
- hydra - our continuous integration system
- NixOS Branding - NixOS branding
Continuous Integration and Distribution
Nixpkgs and NixOS are built and tested by our continuous integration system, Hydra.
- Continuous package builds for unstable/master
- Continuous package builds for the NixOS 25.11 release
- Tests for unstable/master
- Tests for the NixOS 25.11 release
Artifacts successfully built with Hydra are published to cache at https://cache.nixos.org/. When successful build and test criteria are met, the Nixpkgs expressions are distributed via Nix channels.
Contributing
Nixpkgs is among the most active projects on GitHub. While thousands of open issues and pull requests might seem like a lot at first, it helps to consider it in the context of the scope of the project. Nixpkgs describes how to build tens of thousands of pieces of software and implements a Linux distribution. The GitHub Insights page gives a sense of the project activity.
Community contributions are always welcome through GitHub Issues and Pull Requests.
For more information about contributing to the project, please visit the contributing page.
Donations
The infrastructure for NixOS and related projects is maintained by a nonprofit organization, the NixOS Foundation. To ensure the continuity and expansion of the NixOS infrastructure, we are looking for donations to our organization.
You can donate to the NixOS foundation through SEPA bank transfers or by using Open Collective:
License
Nixpkgs is licensed under the MIT License.
Note
MIT license does not apply to the packages built by Nixpkgs, merely to the files in this repository (the Nix expressions, build scripts, NixOS modules, etc.). It also might not apply to patches included in Nixpkgs, which may be derivative works of the packages to which they apply. The aforementioned artifacts are all covered by the licenses of the respective packages.