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.fChecked)
        return true;
    
    
    if (!CheckBlockHeader(block, state, consensusParams, fCheckPOW))
        return false;
    
    if (fCheckMerkleRoot) {
        bool mutated;
        uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
        if (block.hashMerkleRoot != hashMerkleRoot2)
            return state.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-txnmrklroot", "hashMerkleRoot mismatch");
        
        
        
        if (mutated)
            return state.Invalid(BlockValidationResult::BLOCK_MUTATED, "bad-txns-duplicate", "duplicate transaction");
    }
    
    
    
    
    
    
    if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(block, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT)
        return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS, "bad-blk-length", "size limits failed");