Weird error message from Postgres 18

Hi.

I noticed a weird message error from Postgres 18.

sql reproducible test:
create table inserttest (col1 serial PRIMARY KEY, col2 int4 NOT NULL, col3
text NOT NULL, col4 text NULL);
insert into inserttest select 0 AS col2, NULL AS col3, NULL AS col4;
ERROR: null value in column "col2" of relation "inserttest" violates
not-null constraint
DETAIL: Failing row contains (0, null, null, null).
drop table inserttest;

It seems that the message is confusing.
col2 and col3 IS NOT NULL, but col2 has value 0.

best regards,
Ranier Vilela