## arg 1:  the new package version
post_install() {
  cat << EOF
-- NOTICE --------------------------------------------------------------------------
All unit files have been installed to /lib/systemd/system. This only allows systemd
to be aware of them. It will not register them for automatic activation on boot. Use
'systemctl enable <unit>' to ensure that a unit is started at boot.
------------------------------------------------------------------------------------
EOF

  # this might be installed at the same time as systemd which means that it's
  # not running yet. the daemon-reload call will fail with a bogus error.
  post_upgrade 2>/dev/null
}

post_upgrade() {
  # reread all known unit files
  ps hp 1 o comm | {
    read argv0 _
    [ "$argv0" = "systemd" ] && systemctl daemon-reload || :
  } || :
} >/dev/null 2>&1