diff --git a/src/test/isolation/expected/detach-partition-concurrently-3.out b/src/test/isolation/expected/detach-partition-concurrently-3.out
index bbb9d151fb..96ee090d53 100644
--- a/src/test/isolation/expected/detach-partition-concurrently-3.out
+++ b/src/test/isolation/expected/detach-partition-concurrently-3.out
@@ -1,6 +1,6 @@
 Parsed test spec with 2 sessions
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1describe s1alter
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1describe s1alter
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -8,12 +8,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1describe: SELECT 'd3_listp' AS root, * FROM pg_partition_tree('d3_listp')
 					  UNION ALL SELECT 'd3_listp1', * FROM pg_partition_tree('d3_listp1');
@@ -25,7 +26,7 @@ d3_listp1      d3_listp1                     t              0
 step s1alter: ALTER TABLE d3_listp1 ALTER a DROP NOT NULL;
 ERROR:  cannot alter partition "d3_listp1" with an incomplete detach
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1insert s1c
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1insert s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -33,17 +34,18 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1insert: INSERT INTO d3_listp VALUES (1);
 ERROR:  no partition of relation "d3_listp" found for row
 step s1c: COMMIT;
 
-starting permutation: s2snitch s1brr s1s s2detach s1cancel s1insert s1c s1spart
+starting permutation: s2snitch s1brr s1s s2detach s1cancel s2noop s1insert s1c s1spart
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
 step s1s: SELECT * FROM d3_listp;
@@ -51,12 +53,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1insert: INSERT INTO d3_listp VALUES (1);
 step s1c: COMMIT;
 step s1spart: SELECT * FROM d3_listp1;
@@ -65,7 +68,7 @@ a
 1              
 1              
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1insertpart
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1insertpart
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -73,16 +76,17 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1insertpart: INSERT INTO d3_listp1 VALUES (1);
 
-starting permutation: s2snitch s1b s1s s2detach2 s1cancel s1c s1brr s1insert s1s s1insert s1c
+starting permutation: s2snitch s1b s1s s2detach2 s1cancel s2noop s1c s1brr s1insert s1s s1insert s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -90,12 +94,13 @@ a
 
 1              
 step s2detach2: ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach2: <... completed>
 error in steps s1cancel s2detach2: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
 step s1insert: INSERT INTO d3_listp VALUES (1);
@@ -107,7 +112,7 @@ a
 step s1insert: INSERT INTO d3_listp VALUES (1);
 step s1c: COMMIT;
 
-starting permutation: s2snitch s1b s1s s2detach2 s1cancel s1c s1brr s1s s1insert s1s s1c
+starting permutation: s2snitch s1b s1s s2detach2 s1cancel s2noop s1c s1brr s1s s1insert s1s s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -115,12 +120,13 @@ a
 
 1              
 step s2detach2: ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach2: <... completed>
 error in steps s1cancel s2detach2: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1brr: BEGIN ISOLATION LEVEL REPEATABLE READ;
 step s1s: SELECT * FROM d3_listp;
@@ -135,7 +141,7 @@ a
 1              
 step s1c: COMMIT;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1drop s1list
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1drop s1list
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -143,12 +149,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1drop: DROP TABLE d3_listp;
 step s1list: SELECT relname FROM pg_catalog.pg_class
@@ -156,7 +163,7 @@ step s1list: SELECT relname FROM pg_catalog.pg_class
 relname        
 
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1trunc s1spart
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1trunc s1spart
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -164,12 +171,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1trunc: TRUNCATE TABLE d3_listp;
 step s1spart: SELECT * FROM d3_listp1;
@@ -177,7 +185,7 @@ a
 
 1              
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s2detach2 s1c
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s2detach2 s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -185,17 +193,18 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s2detach2: ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY;
 ERROR:  partition "d3_listp1" already pending detach in partitioned table "public.d3_listp"
 step s1c: COMMIT;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s2detachfinal s1c s2detach2
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s2detachfinal s1c s2detach2
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -203,18 +212,19 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE; <waiting ...>
 step s1c: COMMIT;
 step s2detachfinal: <... completed>
 step s2detach2: ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1droppart s2detach2
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1droppart s2detach2
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -222,17 +232,18 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1droppart: DROP TABLE d3_listp1;
 step s2detach2: ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s2begin s2drop s1s s2commit
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s2begin s2drop s1s s2commit
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -240,12 +251,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s2begin: BEGIN;
 step s2drop: DROP TABLE d3_listp1;
@@ -255,7 +267,7 @@ step s1s: <... completed>
 a              
 
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1b s1spart s2detachfinal s1c
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1b s1spart s2detachfinal s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -263,12 +275,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1b: BEGIN;
 step s1spart: SELECT * FROM d3_listp1;
@@ -279,7 +292,7 @@ step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE; <w
 step s1c: COMMIT;
 step s2detachfinal: <... completed>
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1b s1s s2detachfinal s1c
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1b s1s s2detachfinal s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -287,12 +300,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -301,7 +315,7 @@ a
 step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE;
 step s1c: COMMIT;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s1b s1spart s2detachfinal s1c
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s1b s1spart s2detachfinal s1c
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -309,12 +323,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s1b: BEGIN;
 step s1spart: SELECT * FROM d3_listp1;
@@ -325,7 +340,7 @@ step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE; <w
 step s1c: COMMIT;
 step s2detachfinal: <... completed>
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s2begin s2detachfinal s2commit
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s2begin s2detachfinal s2commit
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -333,18 +348,19 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s2begin: BEGIN;
 step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE;
 step s2commit: COMMIT;
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s2begin s2detachfinal s1spart s2commit
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s2begin s2detachfinal s1spart s2commit
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -352,12 +368,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s2begin: BEGIN;
 step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE;
@@ -368,7 +385,7 @@ a
 
 1              
 
-starting permutation: s2snitch s1b s1s s2detach s1cancel s1c s2begin s2detachfinal s1insertpart s2commit
+starting permutation: s2snitch s1b s1s s2detach s1cancel s2noop s1c s2begin s2detachfinal s1insertpart s2commit
 step s2snitch: INSERT INTO d3_pid SELECT pg_backend_pid();
 step s1b: BEGIN;
 step s1s: SELECT * FROM d3_listp;
@@ -376,12 +393,13 @@ a
 
 1              
 step s2detach: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; <waiting ...>
-step s1cancel: SELECT pg_cancel_backend(pid) FROM d3_pid;
-pg_cancel_backend
+step s1cancel: SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid;
+pg_cancel_backendpg_sleep       
 
-t              
+t                             
 step s2detach: <... completed>
 error in steps s1cancel s2detach: ERROR:  canceling statement due to user request
+step s2noop: UNLISTEN noop;
 step s1c: COMMIT;
 step s2begin: BEGIN;
 step s2detachfinal: ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE;
diff --git a/src/test/isolation/specs/detach-partition-concurrently-3.spec b/src/test/isolation/specs/detach-partition-concurrently-3.spec
index 5a8351fc83..13ad84ac03 100644
--- a/src/test/isolation/specs/detach-partition-concurrently-3.spec
+++ b/src/test/isolation/specs/detach-partition-concurrently-3.spec
@@ -1,4 +1,8 @@
 # Try various things to happen to a partition with an incomplete detach
+#
+# Note: Always keep "s2noop" right after "s1cancel" in permutations.  This
+# reduces the probability of the timing problem that the cancel error report
+# is shown together with the next query instead of with the cancel query.
 
 setup
 {
@@ -18,7 +22,8 @@ step "s1b"			{ BEGIN; }
 step "s1brr"		{ BEGIN ISOLATION LEVEL REPEATABLE READ; }
 step "s1s"			{ SELECT * FROM d3_listp; }
 step "s1spart"		{ SELECT * FROM d3_listp1; }
-step "s1cancel"		{ SELECT pg_cancel_backend(pid) FROM d3_pid; }
+# Sleep 0.1s after sending cancel, to give s2 time to react
+step "s1cancel" 	{ SELECT pg_cancel_backend(pid), pg_sleep(0.1) FROM d3_pid; }
 step "s1c"			{ COMMIT; }
 step "s1alter"		{ ALTER TABLE d3_listp1 ALTER a DROP NOT NULL; }
 step "s1insert"		{ INSERT INTO d3_listp VALUES (1); }
@@ -36,43 +41,44 @@ step "s2begin"		{ BEGIN; }
 step "s2snitch"		{ INSERT INTO d3_pid SELECT pg_backend_pid(); }
 step "s2detach"		{ ALTER TABLE d3_listp DETACH PARTITION d3_listp1 CONCURRENTLY; }
 step "s2detach2"	{ ALTER TABLE d3_listp DETACH PARTITION d3_listp2 CONCURRENTLY; }
+step "s2noop"		{ UNLISTEN noop; }
 step "s2detachfinal"	{ ALTER TABLE d3_listp DETACH PARTITION d3_listp1 FINALIZE; }
 step "s2drop"		{ DROP TABLE d3_listp1; }
 step "s2commit"		{ COMMIT; }
 
 # Try various things while the partition is in "being detached" state, with
 # no session waiting.
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1describe" "s1alter"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1insert" "s1c"
-permutation "s2snitch" "s1brr" "s1s" "s2detach" "s1cancel" "s1insert" "s1c" "s1spart"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1insertpart"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1describe" "s1alter"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1insert" "s1c"
+permutation "s2snitch" "s1brr" "s1s" "s2detach" "s1cancel" "s2noop" "s1insert" "s1c" "s1spart"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1insertpart"
 
 # Test partition descriptor caching
-permutation "s2snitch" "s1b" "s1s" "s2detach2" "s1cancel" "s1c" "s1brr" "s1insert" "s1s" "s1insert" "s1c"
-permutation "s2snitch" "s1b" "s1s" "s2detach2" "s1cancel" "s1c" "s1brr" "s1s" "s1insert" "s1s" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach2" "s1cancel" "s2noop" "s1c" "s1brr" "s1insert" "s1s" "s1insert" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach2" "s1cancel" "s2noop" "s1c" "s1brr" "s1s" "s1insert" "s1s" "s1c"
 
 # "drop" here does both tables
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1drop" "s1list"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1drop" "s1list"
 # "truncate" only does parent, not partition
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1trunc" "s1spart"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1trunc" "s1spart"
 
 # If a partition pending detach exists, we cannot drop another one
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2detach2" "s1c"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2detachfinal" "s1c" "s2detach2"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1droppart" "s2detach2"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s2detach2" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s2detachfinal" "s1c" "s2detach2"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1droppart" "s2detach2"
 
 # When a partition with incomplete detach is dropped, we grab lock on parent too.
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s2begin" "s2drop" "s1s" "s2commit"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s2begin" "s2drop" "s1s" "s2commit"
 
 # Partially detach, then select and try to complete the detach.  Reading
 # from partition blocks (AEL is required on partition); reading from parent
 # does not block.
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1b" "s1spart" "s2detachfinal" "s1c"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1b" "s1s" "s2detachfinal" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1b" "s1spart" "s2detachfinal" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1b" "s1s" "s2detachfinal" "s1c"
 
 # DETACH FINALIZE in a transaction block. No insert/select on the partition
 # is allowed concurrently with that.
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s1b" "s1spart" "s2detachfinal" "s1c"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s2begin" "s2detachfinal" "s2commit"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s2begin" "s2detachfinal" "s1spart" "s2commit"
-permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s1c" "s2begin" "s2detachfinal" "s1insertpart" "s2commit"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s1b" "s1spart" "s2detachfinal" "s1c"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s2begin" "s2detachfinal" "s2commit"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s2begin" "s2detachfinal" "s1spart" "s2commit"
+permutation "s2snitch" "s1b" "s1s" "s2detach" "s1cancel" "s2noop" "s1c" "s2begin" "s2detachfinal" "s1insertpart" "s2commit"