post_install() {
  echo '==> You need to make some configuration changes to use duo_unix'
  echo '==> Instructions can be found here: https://www.duosecurity.com/docs/duounix'
  echo '==> Make sure to use /usr/bin/login_duo rather than /usr/sbin/login_duo'
}

post_upgrade() {
  if [[ $(vercmp $2 1.9-3) -lt 0 ]]; then
    echo '==> login_duo has moved to /usr/bin alongside all binaries'
    echo '==> Please update this path in your scripts or configs if applicable'
  fi
}