intermittent issue in feature_bip68_sequence.py: sequence_value = utxos[j][“confirmations”] IndexError: list index out of range #32334

1. 
   maflcko commented at 7:48 am on April 24, 2025: member

   https://cirrus-ci.com/task/5337593233014784?logs=ci#L3671

   0 test  2025-04-23T20:13:04.883000Z TestFramework (ERROR): Unexpected exception caught during testing 
   1                                   Traceback (most recent call last):
   2                                     File "/ci_container_base/test/functional/test_framework/test_framework.py", line 182, in main
   3                                       self.run_test()
   4                                     File "/ci_container_base/ci/scratch/build-i686-pc-linux-gnu/test/functional/feature_bip68_sequence.py", line 70, in run_test
   5                                       self.test_sequence_lock_confirmed_inputs()
   6                                     File "/ci_container_base/ci/scratch/build-i686-pc-linux-gnu/test/functional/feature_bip68_sequence.py", line 173, in test_sequence_lock_confirmed_inputs
   7                                       sequence_value = utxos[j]["confirmations"]
   8                                                        ~~~~~^^^
   9                                   IndexError: list index out of range
   

2. maflcko added the label CI failed on Apr 24, 2025
3. 
   theStack commented at 2:59 pm on April 24, 2025: contributor

   I can reproduce this issue locally by passing the randomseed as shown in the CI logs, i.e.

   0$ ./build/test/functional/feature_bip68_sequence.py --randomseed 6169832640268785903
   

   Seems that the number of UTXOs generated in the test_sequence_lock_confirmed_inputs sub-test (currently 200) is not enough in some cases. A simple minimal-diff fix might be to simply increase that number in this line:

   https://github.com/bitcoin/bitcoin/blob/458720e5e98c6e9103aea1fdfcd39bafc26c27bb/test/functional/feature_bip68_sequence.py#L137

   IIUC, in the absolute worst-case 4000 UTXOs are consumed (400 txs with 10 inputs each).

4. maflcko added the label Tests on May 6, 2025
5. fanquake referenced this in commit fa183045a1 on Jun 19, 2025
6. fanquake closed this on Jun 19, 2025

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