Nix/doc/manual/src/installation/upgrading.md

Upgrading Nix

Note

These upgrade instructions apply for regular Linux distributions where Nix was installed following the installation instructions in this manual.

First, find the name of the current channel through which Nix is distributed:

$ nix-channel --list

By default this should return an entry for Nixpkgs:

nixpkgs https://nixos.org/channels/nixpkgs-23.05

Check which Nix version will be installed:

$ nix-shell -p nix -I nixpkgs=channel:nixpkgs-23.11 --run "nix --version"
nix (Nix) 2.18.1

Warning

Writing to the local store with a newer version of Nix, for example by building derivations with nix-build or nix-store --realise, may change the database schema! Reverting to an older version of Nix may therefore require purging the store database before it can be used.

Update the channel entry:

$ nix-channel --remove nixpkgs
$ nix-channel --add https://nixos.org/channels/nixpkgs-23.11 nixpkgs

Multi-user Nix users on macOS can upgrade Nix by running: sudo -i sh -c 'nix-channel --update && nix-env --install --attr nixpkgs.nix && launchctl remove org.nixos.nix-daemon && launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist'

Single-user installations of Nix should run this: nix-channel --update; nix-env --install --attr nixpkgs.nix nixpkgs.cacert

Multi-user Nix users on Linux should run this with sudo: nix-channel --update; nix-env --install --attr nixpkgs.nix nixpkgs.cacert; systemctl daemon-reload; systemctl restart nix-daemon