This should now be ready to upload (ish).

debian/lubuntu-update-notifier.postinst

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -e
+
+# This file can be removed following the release of Lubuntu 24.04 LTS
+# It's to ensure a smooth transition between the autostart file and the new
+# systemd user units provided
+
+rm -f /etc/xdg/autostart/upg-notifier-autostart.desktop
+rm -f /home/*/.config/autostart/upg-notifier-autostart.desktop
+
+#DEBHELPER#

lubuntu-upg-notifier.sh

@@ -16,21 +16,18 @@
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-while true;
+OUT=`/usr/lib/update-notifier/apt-check 2>&1`
-    do
+oldIFS=$IFS
-        OUT=`/usr/lib/update-notifier/apt-check 2>&1`
+IFS=';'
-        oldIFS=$IFS
+j=0
-        IFS=';'
+for STRING in $OUT; do
-        j=0
+    case $j in
-        for STRING in $OUT; do
+	0)
-            case $j in
+	    UPG=$STRING;;
-                0)
+	1)
-                    UPG=$STRING;;
+	    SEC=$STRING;;
-                1)
+    esac
-                    SEC=$STRING;;
+     j=`expr $j + 1`
-            esac
+done
-             j=`expr $j + 1`
+IFS=$oldIFS
-        done
+/usr/libexec/lubuntu-update-notifier/lubuntu-notifier.py -u $UPG -s $SEC -p /usr/bin/lubuntu-upgrader
-        IFS=$oldIFS
-        /usr/libexec/lubuntu-update-notifier/lubuntu-notifier.py -u $UPG -s $SEC -p /usr/bin/lubuntu-upgrader
-done;