Uninstalling Nix

Multi User

Removing a multi-user installation 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 ~root/.cache/nix

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

Updating to macOS 15 Sequoia

If you recently updated to macOS 15 Sequoia and are getting

error: the user '_nixbld1' in the group 'nixbld' does not exist

when running Nix commands, refer to GitHub issue NixOS/nix#10892 for instructions to fix your installation without reinstalling.

  1. If system-wide shell initialisation files haven't been altered since installing Nix, use the backups made by the installer:

    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

    Otherwise, 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

  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

    by setting the cursor on the respective line using the arrow keys, and pressing dd, and then :wq to save the file.

    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:

    if [ -f /etc/synthetic.conf ]; then
  if [ "$(cat /etc/synthetic.conf)" = "nix" ]; then
    sudo rm /etc/synthetic.conf
  else
    sudo vi /etc/synthetic.conf
  fi
fi

    This will prevent the creation of the empty /nix directory.

  6. Remove the files Nix added to your system, except for the store:

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

  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 find a "Nix Store" volume, delete it by running diskutil apfs deleteVolume with the store volume's diskXsY identifier.

    If you get an error that the volume is in use by the kernel, reboot and immediately delete the volume before starting any other process.

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.

Single User

To remove a single-user installation of Nix, run:

$ rm -rf /nix ~/.nix-channels ~/.nix-defexpr ~/.nix-profile

You might also want to manually remove references to Nix from your ~/.profile.