if spell_ok $SPELL; then
  local OLD_SPELL_VERSION="" &&
  OLD_SPELL_VERSION="$(installed_version ${SPELL})" &&

  if [[ "${OLD_SPELL_VERSION}" != "${VERSION}" ]]; then
    message "${MESSAGE_COLOR}This is a possibly incompatible update of ${SPELL_COLOR}${SPELL}${NO_COLOR}${MESSAGE_COLOR}...${DEFAULT_COLOR}"
    message "${MESSAGE_COLOR}Figuring out what spells need to be checked, this may take a while.${DEFAULT_COLOR}"
    for each in $(show_up_depends $SPELL); do
      if gaze install $each | xargs readelf -d 2> /dev/null |
         grep -q "NEEDED.*libvpx\.so"; then
           up_trigger $each check_self
      fi
    done
  fi
fi