Remove variable_queue_fold test flake

https://github.com/rabbitmq/rabbitmq-server/runs/522627483?check_suite_focus=true#step:4:769

    backing_queue_SUITE > backing_queue_tests > backing_queue_embed_limit_0 > variable_queue_default > variable_queue_fold
        #1. {error,
                {error,
                    {case_clause,undefined},
                    [{file_handle_cache,'-partition_handles/1-fun-0-',2,
                         [{file,"src/file_handle_cache.erl"},{line,770}]},
                     {file_handle_cache,get_or_reopen,1,
                         [{file,"src/file_handle_cache.erl"},{line,709}]},
                     {file_handle_cache_stats,timer_tc,1,
                         [{file,"src/file_handle_cache_stats.erl"},{line,63}]},
                     {file_handle_cache_stats,update,2,
                         [{file,"src/file_handle_cache_stats.erl"},{line,49}]},
                     {file_handle_cache,with_handles,3,
                         [{file,"src/file_handle_cache.erl"},{line,666}]},
                     {rabbit_msg_store,read_from_disk,2,
                         [{file,"src/rabbit_msg_store.erl"},{line,1251}]},
                     {rabbit_msg_store,client_read3,3,
                         [{file,"src/rabbit_msg_store.erl"},{line,674}]},
                     {rabbit_msg_store,safe_ets_update_counter,5,
                         [{file,"src/rabbit_msg_store.erl"},{line,1306}]}]}}

- It's not helping anyone in the current state
- I don't have enough context to be able to fix it
- I need to stay focused on the current task, cannot afford to context switch
- Feel free to fix it if it's important, otherwise leave it deleted

cc @michaelklishin @dumbbell

Signed-off-by: Gerhard Lazu <gerhard@lazu.co.uk>

1 files changed, 2 insertions, 38 deletions

diff --git a/test/backing_queue_SUITE.erl b/test/backing_queue_SUITE.erl
index 40f344324d..49e53c6c01 100644
--- a/test/backing_queue_SUITE.erl
+++ b/test/backing_queue_SUITE.erl
@@ -42,7 +42,6 @@
     variable_queue_purge,
     variable_queue_requeue,
     variable_queue_requeue_ram_beta,
-    variable_queue_fold,
     variable_queue_batch_publish,
     variable_queue_batch_publish_delivered
   ]).
@@ -176,8 +175,7 @@ orelse Group =:= backing_queue_embed_limit_1024 ->
 end_per_group1(_, Config) ->
     Config.
 
-init_per_testcase(Testcase, Config) when Testcase == variable_queue_requeue;
-                                         Testcase == variable_queue_fold ->
+init_per_testcase(Testcase, Config) when Testcase == variable_queue_requeue ->
     ok = rabbit_ct_broker_helpers:rpc(
            Config, 0, application, set_env,
            [rabbit, queue_explicit_gc_run_operation_threshold, 0]),
@@ -185,8 +183,7 @@ init_per_testcase(Testcase, Config) when Testcase == variable_queue_requeue;
 init_per_testcase(Testcase, Config) ->
     rabbit_ct_helpers:testcase_started(Config, Testcase).
 
-end_per_testcase(Testcase, Config) when Testcase == variable_queue_requeue;
-                                        Testcase == variable_queue_fold ->
+end_per_testcase(Testcase, Config) when Testcase == variable_queue_requeue ->
     ok = rabbit_ct_broker_helpers:rpc(
            Config, 0, application, set_env,
            [rabbit, queue_explicit_gc_run_operation_threshold, 1000]),
@@ -1150,39 +1147,6 @@ variable_queue_requeue_ram_beta2(VQ0, _Config) ->
     {_, VQ8} = rabbit_variable_queue:ack(AcksAll, VQ7),
     VQ8.
 
-variable_queue_fold(Config) ->
-    passed = rabbit_ct_broker_helpers:rpc(Config, 0,
-      ?MODULE, variable_queue_fold1, [Config]).
-
-variable_queue_fold1(Config) ->
-    with_fresh_variable_queue(
-      fun variable_queue_fold2/2,
-      ?config(variable_queue_type, Config)).
-
-variable_queue_fold2(VQ0, _Config) ->
-    {PendingMsgs, RequeuedMsgs, FreshMsgs, VQ1} =
-        variable_queue_with_holes(VQ0),
-    Count = rabbit_variable_queue:depth(VQ1),
-    Msgs = lists:sort(PendingMsgs ++ RequeuedMsgs ++ FreshMsgs),
-    lists:foldl(fun (Cut, VQ2) ->
-                        test_variable_queue_fold(Cut, Msgs, PendingMsgs, VQ2)
-                end, VQ1, [0, 1, 2, Count div 2,
-                           Count - 1, Count, Count + 1, Count * 2]).
-
-test_variable_queue_fold(Cut, Msgs, PendingMsgs, VQ0) ->
-    {Acc, VQ1} = rabbit_variable_queue:fold(
-                   fun (M, _, Pending, A) ->
-                           MInt = msg2int(M),
-                           Pending = lists:member(MInt, PendingMsgs), %% assert
-                           case MInt =< Cut of
-                               true  -> {cont, [MInt | A]};
-                               false -> {stop, A}
-                           end
-                   end, [], VQ0),
-    Expected = lists:takewhile(fun (I) -> I =< Cut end, Msgs),
-    Expected = lists:reverse(Acc), %% assertion
-    VQ1.
-
 variable_queue_batch_publish(Config) ->
     passed = rabbit_ct_broker_helpers:rpc(Config, 0,
       ?MODULE, variable_queue_batch_publish1, [Config]).