BUG #18173: ERROR: could not identify a comparison function for type unknown

The following bug has been logged on the website:

Bug reference: 18173
Logged by: JennyJennyChen
Email address: 409800246(at)qq(dot)com
PostgreSQL version: 16.0
Operating system: CentOS Linux release 7.9 (Final)
Description:

postgres=# CREATE TABLE test_v(id int,name varchar(30));
CREATE TABLE
postgres=# insert into test_v values(9,'abc'),(9,'def'),(9,'gh'),
(9,'gh');
INSERT 0 4
postgres=# explain (costs off) select distinct
(id,name,'D3Q84xpymM',123,'123') from test_v;
QUERY PLAN
-------------------------------------------------------------
Unique
-> Sort
Sort Key: (ROW(id, name, 'D3Q84xpymM', 123, '123'))
-> Seq Scan on test_v
(4 rows)

postgres=# select distinct (id,name,'D3Q84xpymM',123,'123') from test_v;
ERROR: could not identify a comparison function for type unknown
postgres=#