chainid opcode returns an error

[frank-lim-partior]

System information

Geth version: Network from this [commit](https://github.com/ConsenSys/quorum-dev-quickstart/commit/fa2c4f2038ebdf54ef962e5e7d44bfd444ebb1d8)
OS & Version: Windows/Linux/OSX

Expected behaviour

Read chain id when chainid() opcode is called.

Actual behaviour

Error received when attempting to call this in remix connected to local quorum RPC:
call to ChainIdCaller.getChainId errored: invalid opcode: CHAINID

Steps to reproduce the behaviour

`pragma solidity ^0.7.0;

contract ChainIdCaller {
function getChainId() public view returns (uint256) {
uint256 id;
// solhint-disable-next-line no-inline-assembly
assembly {
id := chainid()
}
return id;
}
}`

1. Use remix to deploy the above contract in a local GoQuorum started from quickstart.
2. Invoke getChainId() from remix.

Backtrace

[backtrace]

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[achraf17]

Hi @frank-part ,
There are two solutions to fix the issue:

1. when compiling your contract, use the --evm-version istanbul flag docs. You have the same config in remix under advanced configuration.
2. upgrade the solidity version to ^0.8.0 and you can use block.chainid directly without assembly code.

function getChainId() public view returns (uint256) {
   return block.chainid;
}

You also need to ensure that you are running on the istanbul fork and that you have specified istanbulBlock in your genesis.

[frank-lim-partior]

Here is the 'config' folder generated by quorum-test-network
goquorum.zip

[antonydenyer]

You need to specify the block height at which to apply the istanbul fork which contains the opcode for requesting the chainid ie you need to configureistanbulBlock - I've updated the original answer to clarify for others.

[frank-lim-partior]

Hi @antonydenyer, can you provide an example or recommend a specific change in my config file?
I don't see any specific mention of istanbulBlock in the example chaind-id-example you have given, where the example was working.

[antonydenyer]

In config/goquorum/data/genesis.json istanbulBlock: 0 is where it's set. The block number should be higher than your current block if applying to an existing network. You need to run geth init after you make the change. In your case you need to add this entry to your genesis files, assuming you are using the defaults you will be using qbft, you need to add istanbulBlock into the config property in both qbft-standard-genesis.json and qbft-enhanced-genesis.json

[frank-lim-partior]

Thank you - this is okay now.