istanbul chainId opcode returns bad value

Steps to reproduce

1. Start ganache-cli using the following command:

ganache-cli -l 8000000 -i 65535 -h 0.0.0.0 -k istanbul

1. Compile/deploy the following contract:

contract ChainIdTest
{
	function chainId()
	public pure returns (uint256 id)
	{
		assembly { id := chainid() }
	}
}

1. Call the chainId() function.

I expect the returned value to be the chainId passed using the -i flag and accessible using await web3.eth.net.getId(); … but I get a value of 1

[dmihal]

Just spent hours debugging this, extremely frustrating.

web3.eth.chainId() should give the same value as the chainId opcode

[Amxx]

Also, while chainID and networkID are not strictly speaking the same thing, in the ETH community, the mainnet and the testnests (rinkey, ropsten, kovan, goerli) have this property that chainID = networkID.

My usage is to be able to verify meta-transaction signatures that target contracts deployed at the same address on multiple network. When running ganache-cli with option -i we assume that this will set both chainId and networkId so that the ganache behaves just like “one more eth testnet”