Collect_set() of non-primitive types

[anusha Mangina]

I have a table defined as:

CREATE TABLE foo (
  id INT,
  start_time STRING,
  name STRING,
  value STRING,
  type STRING
)

The 'name', 'value' and 'type' fields actually describe another object, and
I'd like to turn these into STRUCTs, something like:

CREATE TABLE bar (
  id INT,
  start_time STRING,
  object STRUCT<name: STRING,
    value: STRING,
    type: STRING>
)

However, I'd also like to create a rollup table containing the most recent
result for a given 'id' field. There can be multiple different 'object'
structs for a given combination of 'id' and 'start_time', so I thought I'd
turn this into an array of structs. My ideal rollup table would look like:

CREATE TABLE rollup (
  id INT,
  start_time STRING,
  objects ARRAY<STRUCT<name: STRING,
    value: STRING,
    type: STRING>>
)

However, I can't do this because the following query fails:

INSERT OVERWRITE TABLE rollup
SELECT id, start_time, collect_set(object)
FROM bar
GROUP BY id, start_time

Here's the error I get:

FAILED: UDFArgumentTypeException Only primitive type arguments are accepted
but struct<name:string,value:string,type:string> was passed as parameter 1.

Is there any way I can do this?