cassert: array size exceeds the maximum allowed (134217727)

I'm getting a failed assertion on 8.4b1.  With cassert off it crashes
the postmaster.  The assertion is:
ERROR:  array size exceeds the maximum allowed (134217727)

Here is the query:select * from (select generate_series(1,500) as id) c  left outer
join foo_status a on c.id = a.id;

note: replacing generate_series with table still gives the error.

create or replace view foo_status as select * from (   select foo_id as id,    array_to_string(array_agg(jc.name), ',
') as jc_list   from foo_session   left join (select * from bat where finished is null) q     using (foo_id)   left
joinbar using (bar_id)   left join baz jc using (baz_id)   where stop is null   group by id, session_start, adb_pid )
q;

all the tables are quite small. foo status runs fine normally and
returns in a couple of msec.

merlin