Uninstalling Nix

Single User

If you have a single-user installation of Nix, uninstall it by running:

$ rm -rf /nix

Multi User

Removing a multi-user installation of Nix is more involved, and depends on the operating system.

Linux

If you are on Linux with systemd:

  1. Remove the Nix daemon service:

    sudo systemctl stop nix-daemon.service
    sudo systemctl disable nix-daemon.socket nix-daemon.service
    sudo systemctl daemon-reload
    

Remove files created by Nix:

sudo rm -rf /etc/nix /etc/profile.d/nix.sh /etc/tmpfiles.d/nix-daemon.conf /nix ~root/.nix-channels ~root/.nix-defexpr ~root/.nix-profile

Remove build users and their group:

for i in $(seq 1 32); do
  sudo userdel nixbld$i
done
sudo groupdel nixbld

There may also be references to Nix in

  • /etc/bash.bashrc
  • /etc/bashrc
  • /etc/profile
  • /etc/zsh/zshrc
  • /etc/zshrc

which you may remove.

macOS

  1. Edit /etc/zshrc, /etc/bashrc, and /etc/bash.bashrc to remove the lines sourcing nix-daemon.sh, which should look like this:

    # Nix
    if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
      . '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
    fi
    # End Nix
    

    If these files haven't been altered since installing Nix you can simply put the backups back in place:

    sudo mv /etc/zshrc.backup-before-nix /etc/zshrc
    sudo mv /etc/bashrc.backup-before-nix /etc/bashrc
    sudo mv /etc/bash.bashrc.backup-before-nix /etc/bash.bashrc
    

    This will stop shells from sourcing the file and bringing everything you installed using Nix in scope.

  2. Stop and remove the Nix daemon services:

    sudo launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
    sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
    sudo launchctl unload /Library/LaunchDaemons/org.nixos.darwin-store.plist
    sudo rm /Library/LaunchDaemons/org.nixos.darwin-store.plist
    

    This stops the Nix daemon and prevents it from being started next time you boot the system.

  3. Remove the nixbld group and the _nixbuildN users:

    sudo dscl . -delete /Groups/nixbld
    for u in $(sudo dscl . -list /Users | grep _nixbld); do sudo dscl . -delete /Users/$u; done
    

    This will remove all the build users that no longer serve a purpose.

  4. Edit fstab using sudo vifs to remove the line mounting the Nix Store volume on /nix, which looks like UUID=<uuid> /nix apfs rw,noauto,nobrowse,suid,owners or LABEL=Nix\040Store /nix apfs rw,nobrowse. This will prevent automatic mounting of the Nix Store volume.

  5. Edit /etc/synthetic.conf to remove the nix line. If this is the only line in the file you can remove it entirely, sudo rm /etc/synthetic.conf. This will prevent the creation of the empty /nix directory to provide a mountpoint for the Nix Store volume.

  6. Remove the files Nix added to your system:

    sudo rm -rf /etc/nix /var/root/.nix-profile /var/root/.nix-defexpr /var/root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels
    

    This gets rid of any data Nix may have created except for the store which is removed next.

  7. Remove the Nix Store volume:

    sudo diskutil apfs deleteVolume /nix
    

    This will remove the Nix Store volume and everything that was added to the store.

    If the output indicates that the command couldn't remove the volume, you should make sure you don't have an unmounted Nix Store volume. Look for a "Nix Store" volume in the output of the following command:

    diskutil list
    

    If you do see a "Nix Store" volume, delete it by re-running the diskutil deleteVolume command, but replace /nix with the store volume's diskXsY identifier.

Note

After you complete the steps here, you will still have an empty /nix directory. This is an expected sign of a successful uninstall. The empty /nix directory will disappear the next time you reboot.

You do not have to reboot to finish uninstalling Nix. The uninstall is complete. macOS (Catalina+) directly controls root directories and its read-only root will prevent you from manually deleting the empty /nix mountpoint.