When gnome-session is invoked with G_MESSAGES_DEBUG=all set, $REGION
will also contain dconf's debug output:

    $ G_MESSAGES_DEBUG=all gsettings get org.gnome.system.locale region
    (process:14005): dconf-DEBUG: 15:59:46.581: watch_fast: "/system/locale/" (establishing: 0, active: 0)
    'de_DE.UTF-8'
    (process:14005): dconf-DEBUG: 15:59:46.582: unwatch_fast: "/system/locale/" (active: 0, establishing: 1)

Avoid that by setting G_MESSAGES_DEBUG empty.