if sudo yunohost backup list | grep -q $app-before-upgrade$backup_number > /dev/null 2>&1; then # Vérifie l'existence de l'archive avant de supprimer l'application et de restaurer
then
sudo yunohost app remove $app # Supprime l'application avant de la restaurer.
sudo yunohost backup restore --ignore-hooks $app-before-upgrade$backup_number --apps $app --force # Restore the backup if upgrade failed
ynh_die "The app was restored to the way it was before the failed upgrade."