# On niv running on mac, which branch should I use to update to 21.11? I can't find release-21.11-darwin branch on nixpkgs

**URL:** https://discourse.nixos.org/t/on-niv-running-on-mac-which-branch-should-i-use-to-update-to-21-11-i-cant-find-release-21-11-darwin-branch-on-nixpkgs/16446
**Category:** Help
**Created:** [December 6, 2021, 1:37am UTC](https://discourse.nixos.org/t/on-niv-running-on-mac-which-branch-should-i-use-to-update-to-21-11-i-cant-find-release-21-11-darwin-branch-on-nixpkgs/16446 "2021-12-06T01:37:05Z")
**Posts on this page:** 1
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### Author: ![ElvishJerricco](https://discourse.nixos.org/user_avatar/discourse.nixos.org/elvishjerricco/32/984_2.png) [@ElvishJerricco](https://discourse.nixos.org/u/ElvishJerricco)
#### Post date: [December 6, 2021, 7:54am UTC](https://discourse.nixos.org/t/on-niv-running-on-mac-which-branch-should-i-use-to-update-to-21-11-i-cant-find-release-21-11-darwin-branch-on-nixpkgs/16446/7 "2021-12-06T07:54:52Z")

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There was no `release-21.05-darwin` branch either. There was `nixpkgs-21.05-darwin` and there is `nixpkgs-21.11-darwin`.

There’s two kinds of branches in question here. There’s the `release-XX.YY` branches, which are the active development branches for that release. Then there are the channel branches; i.e. `nixos-XX.YY` or `nixpkgs-XX.YY-darwin`. The channel branches are updated to a commit from the corresponding `release-XX.YY` branch whenever a commit on that branch passes the tests for that channel on Hydra. So `nixpkgs-XX.YY-darwin` always points to a commit from `release-XX.YY` that has successfully passed the darwin tests on Hydra, and `nixos-XX.YY` points to a commit that passes NixOS’s tests.

In the same vein, `nixos-unstable` and `master` share this same type of relationship; `nixos-unstable` always points to the latest commit on `master` that has passed NixOS’s tests, and `nixpkgs-unstable` points to the latest commit on `master` that passes a set of tests that doesn’t include unnecessary NixOS-specific things.

TL;DR: Never follow `release-XX.YY` branches or `master`. Always follow one of the channel branches; `nixpkgs-XX.YY-darwin` for macOS.

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_[View the full topic](https://discourse.nixos.org/t/on-niv-running-on-mac-which-branch-should-i-use-to-update-to-21-11-i-cant-find-release-21-11-darwin-branch-on-nixpkgs/16446)._