"invalid opcode" when reading chain id from inline assembly

[PaulRBerg]

Expected Behavior

The chain id should be accessible via inline assembly, as this is a feature available since solidity 0.5.12.

Current Behavior

The function that attempts to read the chain id fails with the following error:

Error: VM Exception while processing transaction: invalid opcode
  at HttpProvider.send (node_modules/@nomiclabs/buidler/src/internal/core/providers/http.ts:36:34)
  at /Users/paulrberg/Workspace/Pad/buidler-invalid-opcode/node_modules/@nomiclabs/buidler/src/internal/core/providers/gas-providers.ts:115:21
  at Proxy.cloningSendWrapper (node_modules/@nomiclabs/buidler/src/internal/core/providers/wrapper.ts:9:12)
  at /Users/paulrberg/Workspace/Pad/buidler-invalid-opcode/node_modules/@nomiclabs/buidler/src/internal/core/providers/accounts.ts:219:21
  at Proxy.cloningSendWrapper (node_modules/@nomiclabs/buidler/src/internal/core/providers/wrapper.ts:9:12)
  at /Users/paulrberg/Workspace/Pad/buidler-invalid-opcode/node_modules/@nomiclabs/buidler/src/internal/core/providers/gas-providers.ts:63:21
  at Proxy.cloningSendWrapper (node_modules/@nomiclabs/buidler/src/internal/core/providers/wrapper.ts:9:12)
  at /Users/paulrberg/Workspace/Pad/buidler-invalid-opcode/node_modules/@nomiclabs/buidler/src/internal/core/providers/gas-providers.ts:41:21
  at Proxy.cloningSendWrapper (node_modules/@nomiclabs/buidler/src/internal/core/providers/wrapper.ts:9:12)
  at EthersProviderWrapper.send (node_modules/@nomiclabs/buidler-ethers/src/ethers-provider-wrapper.ts:13:48)
  at EthersProviderWrapper.<anonymous> (node_modules/@ethersproject/providers/src.ts/json-rpc-provider.ts:439:31)
  at step (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:46:23)
  at Object.next (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:27:53)
  at /Users/paulrberg/Workspace/Pad/buidler-invalid-opcode/node_modules/@ethersproject/providers/lib/json-rpc-provider.js:21:71
  at new Promise (<anonymous>)
  at __awaiter (node_modules/@ethersproject/providers/lib/json-rpc-provider.js:17:12)

Steps to Reproduce

1. Clone paulrberg/buidler-invalid-opcode
2. Install dependencies with yarn
3. Generate artifacts with yarn run typechain
4. Run the tests with yarn run test and get the same error as above

Context

As explained in this comment, this issue occurs only when the @nomiclabs/buidler-ganache is activated. When the tests are run against an instance of ganache-cli running in parallel, there is no "invalid opcode" error.

I haven't checked whether this has been solved with Hardhat.

Your Environment

• @nomiclabs/buidler@1.4.8
• @nomiclabs/buidler-ganache@1.3.3
• ganache-cli@6.9.0
• node@12.16.3
• macOS@10.15.7

[alcuadrado]

Thanks, @PaulRBerg! I think this is a bug in how we initialize it in the plugin. Will address it soon.

[PaulRBerg]

Great, thanks for confirming, @alcuadrado.

[fvictorio]

This is indeed an issue in hardhat-ganache.

The fix seems simple: add istanbul (and whatever other hardforks are missing) to the hardfork option validator, and then set the hardfork to istanbul. Maybe we should also update the default value, but I'm not sure if that counts as a breaking change.

[alcuadrado]

This is a recurrent question I have. It's unclear if bumping the hardhfork of the network should actually be a breaking change, given that the users normally think of the default value as being "latest mainnet HF".

[fvictorio]

Yeah, I agree. And even if it is a breaking change, it would break things only in extremely edge cases. I don't think it makes sense to be overly rigid with that.