Follow the rule that regression-test-created roles are named "regress_xxx".

contrib/amcheck didn't get the memo either.

contrib/amcheck/expected/check_btree.out

@@ -14,9 +14,9 @@ CREATE INDEX bttest_a_idx ON bttest_a USING btree (id);
 CREATE INDEX bttest_b_idx ON bttest_b USING btree (id);
 CREATE UNIQUE INDEX bttest_multi_idx ON bttest_multi
 USING btree (id) INCLUDE (data);
-CREATE ROLE bttest_role;
+CREATE ROLE regress_bttest_role;
 -- verify permissions are checked (error due to function not callable)
-SET ROLE bttest_role;
+SET ROLE regress_bttest_role;
 SELECT bt_index_check('bttest_a_idx'::regclass);
 ERROR:  permission denied for function bt_index_check
 SELECT bt_index_parent_check('bttest_a_idx'::regclass);
@@ -25,11 +25,11 @@ RESET ROLE;
 -- we, intentionally, don't check relation permissions - it's useful
 -- to run this cluster-wide with a restricted account, and as tested
 -- above explicit permission has to be granted for that.
-GRANT EXECUTE ON FUNCTION bt_index_check(regclass) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_check(regclass, boolean) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass, boolean) TO bttest_role;
-SET ROLE bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_check(regclass) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_check(regclass, boolean) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass, boolean) TO regress_bttest_role;
+SET ROLE regress_bttest_role;
 SELECT bt_index_check('bttest_a_idx');
  bt_index_check 
 ----------------
@@ -166,5 +166,5 @@ DROP TABLE bttest_b;
 DROP TABLE bttest_multi;
 DROP TABLE delete_test_table;
 DROP TABLE toast_bug;
-DROP OWNED BY bttest_role; -- permissions
-DROP ROLE bttest_role;
+DROP OWNED BY regress_bttest_role; -- permissions
+DROP ROLE regress_bttest_role;

contrib/amcheck/sql/check_btree.sql

@@ -18,10 +18,10 @@ CREATE INDEX bttest_b_idx ON bttest_b USING btree (id);
 CREATE UNIQUE INDEX bttest_multi_idx ON bttest_multi
 USING btree (id) INCLUDE (data);
 
-CREATE ROLE bttest_role;
+CREATE ROLE regress_bttest_role;
 
 -- verify permissions are checked (error due to function not callable)
-SET ROLE bttest_role;
+SET ROLE regress_bttest_role;
 SELECT bt_index_check('bttest_a_idx'::regclass);
 SELECT bt_index_parent_check('bttest_a_idx'::regclass);
 RESET ROLE;
@@ -29,11 +29,11 @@ RESET ROLE;
 -- we, intentionally, don't check relation permissions - it's useful
 -- to run this cluster-wide with a restricted account, and as tested
 -- above explicit permission has to be granted for that.
-GRANT EXECUTE ON FUNCTION bt_index_check(regclass) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_check(regclass, boolean) TO bttest_role;
-GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass, boolean) TO bttest_role;
-SET ROLE bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_check(regclass) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_check(regclass, boolean) TO regress_bttest_role;
+GRANT EXECUTE ON FUNCTION bt_index_parent_check(regclass, boolean) TO regress_bttest_role;
+SET ROLE regress_bttest_role;
 SELECT bt_index_check('bttest_a_idx');
 SELECT bt_index_parent_check('bttest_a_idx');
 RESET ROLE;
@@ -110,5 +110,5 @@ DROP TABLE bttest_b;
 DROP TABLE bttest_multi;
 DROP TABLE delete_test_table;
 DROP TABLE toast_bug;
-DROP OWNED BY bttest_role; -- permissions
-DROP ROLE bttest_role;
+DROP OWNED BY regress_bttest_role; -- permissions
+DROP ROLE regress_bttest_role;