case "$MODE" in
    configure)
        unset DEBIAN_HAS_FRONTEND
        unset DEBIAN_FRONTEND
        unset DEBCONF_FRONTEND
        unset DEBCONF_REDIR
        # Avoid debconf mailing notes.
        DEBCONF_ADMIN_EMAIL=""
        export DEBCONF_ADMIN_EMAIL

        DEBCONF_READFD=0
        export DEBCONF_READFD
        DEBCONF_WRITEFD=3
        export DEBCONF_WRITEFD
        DEBIAN_FRONTEND=passthrough
        export DEBIAN_FRONTEND
        ;;
esac
