post_install() {
  /usr/lib/package-manager/nix/init.sh || echo ">>> ERROR: /usr/lib/package-manager/nix/init.sh not found or not executable."
}

post_upgrade() {
  /usr/lib/package-manager/nix/init.sh || echo ">>> ERROR: /usr/lib/package-manager/nix/init.sh not found or not executable."
}

post_remove() {
  echo ">>> package-manager removed. Nix itself was not removed."
}