[Exim] missing or misplaced { or } during mysql expansion

Hi there..

any ideas what's wrong with this?:

manually_routed_relay_to_domains:
  driver = manualroute
  transport = remote_smtp
  domains = +relay_to_domains_manual
  route_list = "* ${sg { ${lookup mysql { \
                               select fe_relay_host from domains \
                               where domain = '${quote_mysql:$domain}'  \
                              } } } {\n} {:} } by_name"

It produces this error:

8699 LOG: MAIN PANIC
8699 failed to expand "${sg" while checking a list: missing or misplaced
{ or }
8699 SMTP>> 451 Temporary local problem - please try later

Any help would be great :-)