etc/apt/apt.conf.d/20packagekit

// THIS FILE IS USED TO INFORM PACKAGEKIT
// THAT THE UPDATE-INFO MIGHT HAVE CHANGED

// Whenever dpkg is called we might have different updates
// i.e. if an user removes a package that had an update
DPkg::Post-Invoke {
"/usr/bin/test -e /usr/share/dbus-1/system-services/org.freedesktop.PackageKit.service && /usr/bin/test -S /var/run/dbus/system_bus_socket && /usr/bin/gdbus call --system --dest org.freedesktop.PackageKit --object-path /org/freedesktop/PackageKit --timeout 4 --method org.freedesktop.PackageKit.StateHasChanged cache-update > /dev/null; /bin/echo > /dev/null";
};

// When Apt's cache is updated (i.e. apt-cache update)
APT::Update::Post-Invoke-Success {
"/usr/bin/test -e /usr/share/dbus-1/system-services/org.freedesktop.PackageKit.service && /usr/bin/test -S /var/run/dbus/system_bus_socket && /usr/bin/gdbus call --system --dest org.freedesktop.PackageKit --object-path /org/freedesktop/PackageKit --timeout 4 --method org.freedesktop.PackageKit.StateHasChanged cache-update > /dev/null; /bin/echo > /dev/null";
};