post_install() {
  grep -Fqx /bin/nu /etc/shells || echo /bin/nu >> /etc/shells
  grep -Fqx /usr/bin/nu /etc/shells || echo /usr/bin/nu >> /etc/shells
}

post_upgrade() {
  post_install
}

pre_remove() {
  sed -i -r '/^(\/usr)?\/bin\/nu$/d' etc/shells
}