diff -U3 /tmp/cirrus-ci-build/contrib/citext/expected/create_index_acl.out /tmp/cirrus-ci-build/build/testrun/citext/regress/results/create_index_acl.out
--- /tmp/cirrus-ci-build/contrib/citext/expected/create_index_acl.out	2024-03-19 00:05:09.489103000 +0000
+++ /tmp/cirrus-ci-build/build/testrun/citext/regress/results/create_index_acl.out	2024-03-19 00:22:30.348498000 +0000
@@ -57,6 +57,7 @@
   WHERE (s.index_row_if(y));
 -- Make the table nonempty.
 INSERT INTO s.x VALUES ('foo'), ('bar');
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 -- If the INSERT runs the planner on index expressions, a search_path change
 -- survives.  As of 2022-06, the INSERT reuses a cached plan.  It does so even
 -- under debug_discard_caches, since each index is new-in-transaction.  If
diff -U3 /tmp/cirrus-ci-build/contrib/citext/expected/citext_1.out /tmp/cirrus-ci-build/build/testrun/citext/regress/results/citext.out
--- /tmp/cirrus-ci-build/contrib/citext/expected/citext_1.out	2024-03-19 00:05:09.489078000 +0000
+++ /tmp/cirrus-ci-build/build/testrun/citext/regress/results/citext.out	2024-03-19 00:22:30.537405000 +0000
@@ -6,6 +6,7 @@
 SELECT amname, opcname
 FROM pg_opclass opc LEFT JOIN pg_am am ON am.oid = opcmethod
 WHERE opc.oid >= 16384 AND NOT amvalidate(opc.oid);
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
  amname | opcname 
 --------+---------
 (0 rows)
@@ -207,6 +208,7 @@
        ('muop28x03'), ('yi3nm0d73')) x(v)
 WHERE  citext_hash(v)::bit(32) != citext_hash_extended(v, 0)::bit(32)
        OR citext_hash(v)::bit(32) = citext_hash_extended(v, 1)::bit(32);
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
  value | standard | extended0 | extended1 
 -------+----------+-----------+-----------
 (0 rows)
@@ -217,6 +219,7 @@
 );
 INSERT INTO try (name)
 VALUES ('a'), ('ab'), ('â'), ('aba'), ('b'), ('ba'), ('bab'), ('AZ');
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 SELECT name, 'a' = name AS eq_a   FROM try WHERE name <> 'â';
  name | eq_a 
 ------+------
@@ -321,6 +324,7 @@
        ('ABA'),
        ('ABC'),
        ('abd');
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 CREATE INDEX srt_name ON srt (name);
 -- Check the min() and max() aggregates, with and without index.
 set enable_seqscan = off;
@@ -2271,6 +2275,7 @@
        ( to_char(  125.7::float4,             '999D9') ),
        ( to_char(  125.9::float8,             '999D9') ),
        ( to_char( -125.8::numeric,            '999D99S') );
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 SELECT COUNT(*) = 19::bigint AS t FROM try;
  t 
 ---
@@ -2302,6 +2307,7 @@
 );
 INSERT INTO citext_table (name)
   VALUES ('one'), ('two'), ('three'), (NULL), (NULL);
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 CREATE MATERIALIZED VIEW citext_matview AS
   SELECT * FROM citext_table;
 CREATE UNIQUE INDEX citext_matview_id
@@ -2310,6 +2316,7 @@
   FROM citext_matview m
   FULL JOIN citext_table t ON (t.id = m.id AND t *= m)
   WHERE t.id IS NULL OR m.id IS NULL;
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
  id | name | id | name 
 ----+------+----+------
 (0 rows)
@@ -2319,6 +2326,7 @@
   FROM citext_matview m
   FULL JOIN citext_table t ON (t.id = m.id AND t *= m)
   WHERE t.id IS NULL OR m.id IS NULL;
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
  id | name | id | name 
 ----+------+----+------
     |      |  2 | Two
@@ -2326,6 +2334,8 @@
 (2 rows)
 
 REFRESH MATERIALIZED VIEW CONCURRENTLY citext_matview;
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
+WARNING:  outfuncs/readfuncs failed to produce an equal rewritten parse tree
 SELECT * FROM citext_matview ORDER BY id;
  id | name  
 ----+-------