`CompareModifiedEntry`, as used in

https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/miner.h#L97-L112

will trigger a compile-time error in many `const` operations of index #1 of `indexed_modified_transaction_set` because `CompareModifiedEntry::operator()` is not `const`.

Most likely related to:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=224129
void operator() (CTxMemPoolModifiedEntry &e)
    {
        e.nModFeesWithAncestors -= iter->GetFee();
        e.nSizeWithAncestors -= iter->GetTxSize();
        e.nSigOpCostWithAncestors -= iter->GetSigOpCost();
    }
    CTxMemPool::txiter iter;
};
class BlockAssembler
{
private:
    
    std::unique_ptr<CBlockTemplate> pblocktemplate;