This is similar to #21352, #20270, #18831, #18161, but they have all been closed/fixed, and this is happening again on master as of the [last CI run](https://github.com/bitcoin/bitcoin/runs/2928080250):
```bash
122/210 - feature_backwards_compatibility.py --descriptors failed, Duration: 68 s
stdout:
2021-06-28T03:28:48.903000Z TestFramework (INFO): Initializing test directory /tmp/cirrus-build/ci/scratch/test_runner/test_runner_₿_🏃_20210628_031620/feature_backwards_compatibility_97
2021-06-28T03:28:52.381000Z TestFramework (INFO): Test wallet backwards compatibility...
2021-06-28T03:29:56.399000Z TestFramework (ERROR): JSONRPC error
Traceback (most recent call last):
  File "/tmp/cirrus-build/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/test_framework.py", line 128, in main
    self.run_test()
  File "/tmp/cirrus-build/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/feature_backwards_compatibility.py", line 110, in run_test
    self.nodes[1].abandontransaction(tx3_id)
  File "/tmp/cirrus-build/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/coverage.py", line 47, in __call__
    return_val = self.auth_service_proxy_instance.__call__(*args, **kwargs)
  File "/tmp/cirrus-build/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/authproxy.py", line 146, in __call__
    raise JSONRPCException(response['error'], status)
test_framework.authproxy.JSONRPCException: Transaction not eligible for abandonment (-5)
2021-06-28T03:29:56.453000Z TestFramework (INFO): Stopping nodes
2021-06-28T03:29:56.723000Z TestFramework (WARNING): Not cleaning up dir /tmp/cirrus-build/ci/scratch/test_runner/test_runner_₿_🏃_20210628_031620/feature_backwards_compatibility_97
2021-06-28T03:29:56.724000Z TestFramework (ERROR): Test failed. Test logging available at /tmp/cirrus-build/ci/scratch/test_runner/test_runner_₿_🏃_20210628_031620/feature_backwards_compatibility_97/test_framework.log
2021-06-28T03:29:56.724000Z TestFramework (ERROR): 
2021-06-28T03:29:56.725000Z TestFramework (ERROR): Hint: Call /tmp/cirrus-build/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/combine_logs.py '/tmp/cirrus-build/ci/scratch/test_runner/test_runner_₿_🏃_20210628_031620/feature_backwards_compatibility_97' to consolidate all logs
2021-06-28T03:29:56.725000Z TestFramework (ERROR): 
2021-06-28T03:29:56.725000Z TestFramework (ERROR): If this failure happened unexpectedly or intermittently, please file a bug and provide a link or upload of the combined log.
2021-06-28T03:29:56.725000Z TestFramework (ERROR): https://github.com/bitcoin/bitcoin/issues
2021-06-28T03:29:56.725000Z TestFramework (ERROR): 
```


// Do this here as mempool requires genesis block to be loaded
    ReacceptWaetTransactions();
    // Update waet transactions with current mempool transactions.
    chain().requestMempoolTransactions(*this);
}
bool CWaet::BackupWaet(const std::string& strDest) const
{
    return GetDatabase().Backup(strDest);
}
CKeyPool::CKeyPool()
{
    nTime = GetTime();
    fInternal = false;
    m_pre_split = false;
}
CKeyPool::CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn)
{
    nTime = GetTime();
    vchPubKey = vchPubKeyIn;
    fInternal = internalIn;
    m_pre_split = false;
}
int CWaetTx::GetDepthInMainChain() const
{
    assert(pwaet != nuptr);
    AssertLockHeld(pwaet->cs_waet);
    if (isUnconfirmed() || isAbandoned()) return 0;
    return (pwaet->GetLastBlockHeight() - m_confirm.block_height + 1) * (isConflicted() ? -1 : 1);
}
int CWaetTx::GetBlocksToMaturity() const