Truffle: `truffle compile` throws InternalCompilerError with no description

[safakoks]

• [x] I've asked for help in the Truffle Gitter before filing this issue.

---

Issue

I have tried to create a test of my contract which includes a function returns Struct instance. But, it returns a meaningless error.

Steps to Reproduce

Here's my contract which is created by Solidity v0.6.0

pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;


contract Stack{

    struct Item{
        string  name;
        uint256 quantity;
        bool isSolid;
    }

    mapping(address => Item[]) userItemsMap;


    function addItem(string memory _name, uint256 _quantity, bool _isSolid) public {
        userItemsMap[msg.sender].push(Item({
        name:_name, quantity:_quantity,
        isSolid :_isSolid
            }));
    }

    function getItems() public view returns(Item[] memory){
        return userItemsMap[msg.sender];
    }

    function getLastItem() public view returns(Item memory){
        Item[] memory userItems = userItemsMap[msg.sender];
        require(userItems.length>0);
        return userItems[userItems.length - 1];
    }

}

And its sample test contract :

pragma solidity ^0.6.0;

import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/Stack.sol";

contract  TestStackContract{

    function testAddingItem() public {

        Stack stackInstance =  Stack(DeployedAddresses.Stack());

        stackInstance.addItem("Apple",125,true);

        Stack.Item memory lastItem = stackInstance.getLastItem();

        Assert.equal(lastItem.name, "Apple", "Name should be Apple");
    }
}

Expected Behavior

I run truffle test and it should pass the test or return an error message

Actual Results

It returns an InternalCompilerError without any error message

Using network 'development'.


Compiling your contracts...
===========================
> Compiling ./test/TestBiddingContract.sol
> Compiling ./test/TestStack.sol

InternalCompilerError:

Compilation failed. See above.
Truffle v5.1.13 (core: 5.1.13)
Node v8.17.0

Environment

• Operating System: Ubuntu 16.04
• Ethereum client: GETH / Quorum
• Truffle version (truffle version): v5.1.13
• node version (node --version): v8.17.0
• npm version (npm --version): 6.13.4

[eggplantzzz]

@safakoks Thanks for reporting this, I'll try and reproduce your error to get to the bottom of this!

[eggplantzzz]

Using Truffle without Geth or Quorum I get the following error

InternalCompilerError: Unknown dynamically sized type: struct Stack.Item memory

It looks like that message comes from the decoder and perhaps Geth/Quorum setups give differently formatted messages? Maybe @haltman-at might understand what is going on here a little bit better than I do.

[safakoks]

Is there any solution for this? Because I could not understand what is wrong and why it happens?

[haltman-at]

InternalCompilerError is a solc error message; it's solc throwing that error, not Truffle. This has nothing to do with the decoder, it's a compilation error.

[haltman-at]

Basically, if you see InternalCompilerError, you should report it to the Solidity team. Unless for some reason compiling those tests only fails in Truffle?

[safakoks]

@haltman-at thanks for your answer, yes it happened because of Solidity. I asked them, why it occurs, they recommend me adding pragma experimental ABIEncoderV2; into Test Contract, It works fine on Remix. But still, truffle does not accept the contract during truffle test

It returns the same error without any message :

Using network 'development'.


Compiling your contracts...
===========================
> Compiling ./contracts/Stack.sol
> Compiling ./test/TestStack.sol

InternalCompilerError:

Compilation failed. See above.
Truffle v5.1.13 (core: 5.1.13)
Node v8.17.0

[CruzMolina]

@safakoks , which version of solidity are you specifically using to compile with while testing?

[safakoks]

@CruzMolina , here's my compile config in truffle-config.js

compilers: {
        solc: {
            version: "0.6.0"
        }
    }

[CruzMolina]

Hmmm. odd. this is what I see

➜  reprod-error truffle test

Compiling your contracts...
===========================
> Compiling ./contracts/Migrations.sol
> Compiling ./contracts/Stack.sol
> Compiling ./test/TestExample.sol

InternalCompilerError: Unknown dynamically sized type: struct Stack.Item memory

Compilation failed. See above.
Truffle v5.1.14 (core: 5.1.14)
Node v10.18.0

Same output when using Node v8.17.0.

[safakoks]

@CruzMolina may it happens because I am using Truffle v5.1.13?

[CruzMolina]

@safakoks Hmmm. No, I'm not seeing any changes to the relevant code in v5.1.14.

At this point, I think we need to see a repo of a truffle project example where this exact bug is consistently reproduced.