Nested CTE query hangs forever

the following query works fine:

with b as (select raw field1 from default d1 limit 1) select raw field2 from default d2 where field1 in b limit 1

But if I nest this query as another CTE it hangs forever:

with a as (<---> with b as (select raw field1 from default d1 limit 1) select raw field2 from default d2 where field1 in b limit 1 <---> ) select 1 limit 1