以太坊POA共识现在存在的问题

// SetCoinbase sets the coinbase of the generated block.
// It can be called at most once.
func (b *BlockGen) SetCoinbase(addr common.Address) {
	if b.gasPool != nil {
		if len(b.txs) > 0 {
			panic("coinbase must be set before adding transactions")
		}
		panic("coinbase can only be set once")
	}
	b.header.Coinbase = addr
	b.gasPool = new(GasPool).AddGas(b.header.GasLimit)
}

// Gather all the proposals that make sense voting on
	addresses := make([]common.Address, 0, len(c.proposals))
	for address, authorize := range c.proposals {
		if snap.validVote(address, authorize) {
			addresses = append(addresses, address)
		}
	}
	// If there's pending proposals, cast a vote on them
	if len(addresses) > 0 {
		header.Coinbase = addresses[rand.Intn(len(addresses))]
		if c.proposals[header.Coinbase] {
			copy(header.Nonce[:], nonceAuthVote)
		} else {
			copy(header.Nonce[:], nonceDropVote)
		}
	}

if root := statedb.IntermediateRoot(v.config.IsEIP158(header.Number)); header.Root != root {
		return fmt.Errorf("invalid merkle root (remote: %x local: %x)", header.Root, root)
	}