https://github.com/bitcoin/bitcoin/blob/68f3c7eb080e461cfeac37f8db7034fe507241d0/src/prevector.h#L152-L158

I'm opening an issue as its fix is too tiny to become a pull request.

Can be solved by renaming the struct to
```c
     struct indirect_contents { 
         size_type capacity; 
         char* indirect; 
     }; 
```
if (block.vtx.empty() || !block.vtx[0]->IsCoinBase())
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-missing", "first tx is not coinbase");
    for (unsigned int i = 1; i < block.vtx.size(); i++)
        if (block.vtx[i]->IsCoinBase())
            return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-cb-multiple", "more than one coinbase");
    
    
    for (const auto& tx : block.vtx) {
        TxValidationState tx_state;
        if (!CheckTransaction(*tx, tx_state)) {
            
            
            assert(tx_state.GetResult() == TxValidationResult::TX_CONSENSUS);
            return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, tx_state.GetRejectReason(),
                                 strprintf("Transaction check failed (tx hash %s) %s", tx->GetHash().ToString(), tx_state.GetDebugMessage()));
        }
    }
    unsigned int nSigOps = 0;
    for (const auto& tx : block.vtx)
    {
        nSigOps += GetLegacySigOpCount(*tx);
    }
    if (nSigOps * WITNESS_SCALE_FACTOR > MAX_BLOCK_SIGOPS_COST)
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-sigops", "out-of-bounds SigOpCount");
    if (fCheckPOW && fCheckMerkleRoot)
        block.fChecked = true;
    return true;
}
bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)