Nixpkgs

linux nix

Definition

Nixpkgs

Nixpkgs is a collection of software packages that can be installed with the Nix package manager. It also implements NixOS, a purely-functional Linux distribution.

Branches

Release and channel branches

Nixpkgs uses two common branch names for a stable release line.

• release-25.11 is the maintenance branch for the 25.11 release line. Backports and urgent fixes usually land here first.
• nixos-25.11 is the corresponding channel branch or stream. It usually follows release-25.11, but it can lag behind.

In a flake, the effective version comes from the locked revision in flake.lock, not only from the URL in flake.nix. Changing the input URL changes where future updates are taken from. The actual fix arrives when the lock is updated to a patched commit and the system is rebuilt.

During a security advisory, prefer the exact branch named in the advisory. If a fix is only on release-*, using nixos-* may leave the system on an older commit.

Contributing to Nixpkgs packages

nixpkgs/pkgs/README.md at d737a9fa467207127823cf445ae02d8984978b5d · NixOS/nixpkgs · GitHub