Custom Types: failure to decode value when Custom Type is used as map key

 CREATE TYPE subject_id (
  ns        text,
  id        text
);

create table test (  id  int PRIMARY KEY, some_column map<subject_id, int>);

update test set some_column[{ns:'xyz.com', id:'userid'}] = 33 where id = 22222;

insert into test (id, some_column) values (444, {{ns:'abc.com', id:'user2'}: 33});

select * from test;

id    | some_column
-------+------------------------------------------------------------------------------
   444 |  '\x00\x01\x00\x12\x00\x07abc.com\x00\x00\x05user2\x00\x00\x04\x00\x00\x00!'
 22222 | '\x00\x01\x00\x13\x00\x07xyz.com\x00\x00\x06userid\x00\x00\x04\x00\x00\x00!'

(2 rows)

Failed to decode value '\x00\x01\x00\x12\x00\x07abc.com\x00\x00\x05user2\x00\x00\x04\x00\x00\x00!' (for column 'some_column') as map<subject_id, int>: unhashable type: 'list'
Failed to decode value '\x00\x01\x00\x13\x00\x07xyz.com\x00\x00\x06userid\x00\x00\x04\x00\x00\x00!' (for column 'some_column') as map<subject_id, int>: unhashable type: 'list'