suid_set=tmp/tup.upgrade.suid_set
binary=/usr/bin/tup

suid_msg() {
  if [ -f $suid_set ]; then
    echo "$binary has suid bit set. It allows you to run commands in chroot-ed environment (e.g. for full dependency tracking)."
    echo "See 'man tup' for more information."
  else
    echo "If you want to be able to run commands in chroot-ed environment (e.g. for full dependency tracking)" \
         "you need to set suid bit on tup binary: 'sudo chmod +s $binary'."
    echo "See 'man tup' for more information."
  fi
}

pre_upgrade() {
  [ -u $binary ] && touch $suid_set
  return 0
}

post_install() {
  suid_msg
  return 0
}

post_upgrade() {
  suid_msg
  [ -f $suid_set ] && chmod +s $binary
  rm -f $suid_set
  return 0
}