feature_taproot: sample tx version border values more #32841

1. 
   instagibbs commented at 9:03 pm on June 30, 2025: member

   Currently if the version 3 is selected for an otherwise standard spender, the test will fail. It’s unlikely but possible, so change the test to update expectations and sample more aggressively on border values to instigate failures much quicker in the future if another version is made standard.
2. feature_taproot: sample tx version border values more

   Currently if the version 3 is selected for an otherwise
   standard spender, the test will fail. It's unlikely but
   possible, so change the test to update expectations and
   sample more aggressively on border values to instigate
   failures much quicker in the future if another version is
   made standard.

   4be81e9746
3. 
   DrahtBot commented at 9:03 pm on June 30, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32841.

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   ACK	darosior, maflcko

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4. darosior approved
5. 
   darosior commented at 9:29 am on July 2, 2025: member

   ACK 4be81e9746e9e18923386d6f4945a33885fd98a7
6. 
   maflcko commented at 10:08 am on July 2, 2025: member

   lgtm ACK 4be81e9746e9e18923386d6f4945a33885fd98a7

   Also tested the failure on current master.

7. fanquake merged this on Jul 2, 2025
8. fanquake closed this on Jul 2, 2025

   ---

9. in test/functional/feature_taproot.py:1541 in 4be81e9746

   1537@@ -1535,8 +1538,7 @@ def test_spenders(self, node, spenders, input_counts):
   1538                 is_standard_tx = (
   1539                     fail_input is None  # Must be valid to be standard
   1540                     and (all(utxo.spender.is_standard for utxo in input_utxos))  # All inputs must be standard
   1541-                    and tx.version >= 1  # The tx version must be standard
   1542-                    and tx.version <= 2)
   1543+                    and tx.version in TX_STANDARD_VERSIONS)  # The tx version must be standard
   

   ---

   ---

   

   maflcko commented at 2:39 pm on July 2, 2025:

   i guess it is not enough and the truc rules need to be checked as well. Otherwise:

   0[10:00:08.436] �[0;36m                                   test_framework.authproxy.JSONRPCException: TRUC-violation, version=3 tx 18cf284e19b7df3927bb95ea6a15d7d710a180bb62ccf18ad05948915c85171f (wtxid=3a4704c5da033ee18e46813915c5bad5747277e40f9684689bb66ed91ac85256) is too big: 25250 > 10000 virtual bytes (-26)�[0m
   

   https://cirrus-ci.com/task/6341200170450944?logs=ci#L2708

   ---

   

   instagibbs commented at 2:43 pm on July 2, 2025:

   There are no in-mempool deps afaik, so checking the vsize of tx should suffice?

   ---

   

   instagibbs commented at 3:09 pm on July 2, 2025:

   opened potential resolution at #32859

   was able to reproduce the issue and not run into it anymore

10. achow101 referenced this in commit 1927432354 on Jul 2, 2025
11. fanquake referenced this in commit 9f3690b978 on Jul 3, 2025
12. 
    fanquake commented at 11:17 am on July 3, 2025: member

    Backported to 29.x in #32863.

Contributors
instagibbs DrahtBot darosior maflcko fanquake