Fail

[trancee]

I got quite some transactions that just say Fail without further information. The bot seems to be running successfully, but somehow there is an error inside the smart contract. However, I have no idea how to debug this?

https://polygonscan.com/tx/0x62db419e8b7d43347e0ddb5e438fe8194bac07a3b520d018a7e89c478320d4f6

[yuichiroaoki]

I got this error too and have no idea what's going on there.

Yes, I agree. It's probably because of the contract.

[gsngsn123]

Fail with error 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT' how can i resolve this error

[yuichiroaoki]

Possible reason

I just happened to know that 1inch api returns the burn address instead of wmatic address.

1inch web UI

1inch api response

That's why the bot passes the burn address instead of wmatic address and the transaction ends up failing without any error messages.

[bpevreall]

I noticed the burn address is also on line 1 & 21 of src/constraints, is this of any relevance? looks out of place to me but im by no means experienced

[yuichiroaoki]

True. I didn't write that part.

Replacing the burn address to wmatic one seems to solve the issue.

[MetaNynja]

The burn address also appears in the contract.

Is this the correct address? : 0x0000000000000000000000000000000000001010

And do you mean replacing the burn address with the Matic address? Looks like WMatic is fine.

Great job spotting that btw.

[MetaNynja]

I updated the Matic address from the burn address to 0x0000000000000000000000000000000000001010 on both the contract and the bot but still hasn't been successful :

https://polygonscan.com/address/0x10A1504aE79e7A1f2e80A299f3E94565673A5165

[bpevreall]

If I'm not mistaken you need WMATIC Address rather than MATIC. https://polygonscan.com/token/0x0d500b1d8e8ef31e21c99d1db9a6444d3adf1270

im getting INSUFFICIENT_OUTPUT_AMOUNT on every tx after making the amendments, have increased slippage to 5% but still the same after rebuild

[MetaNynja]

I'm confused about it being WMatic still. Where I find the burn address is where Matic is stated.

Line 4: exports.polyMatic = "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee";

Line 8: MATIC: { Line 12 :address: "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",

[yuichiroaoki]

That token info is used only at src/debug.ts to debug transactions, so it doesn't fix the error itself.

[MetaNynja]

No sorry, I just mean that I don’t think you meant to say WMatic above, the burn address is listed beside Matic, not WMatic. Did you mean to say we just need to change the burn address to the Matic address?

[MetaNynja]

Any idea why there is a call to selfdestruct to 1inch Network: CHI Token

I don't see an address for CHI anywhere in the code. Since CHI is a gas token for 1inch, do we need to indicate this anywhere?

[yuichiroaoki]

I have no idea about the selfdestruct to 1inch.

I reproduced the "Fail" error here. https://github.com/yuichiroaoki/poly-flash/pull/16

Does it make sense?

it("should be reverted without any error messages when the path includes the burn address.", async () => {
    await impersonateFundErc20(USDC, DAI_WHALE, Flashloan.address, "100.0", 6);
    await expect(
        Flashloan.dodoFlashLoan({
            flashLoanPool: dodoV2Pool.WETH_USDC,
            loanAmount: getBigNumber(1, 6),
            firstRoutes: [{
                path: [erc20Address.USDC, BurnAddress, erc20Address.WETH],
                router: uniswapRouter.quickswap,
            }],
            secondRoutes: [{
                path: [erc20Address.WETH, erc20Address.USDC],
                router: uniswapRouter.quickswap,
            }]
        }, { gasLimit: 1000000 })
    ).to.be.revertedWith("");
});

[MetaNynja]

In the test error folders there is the following :

            .emit(Flashloan, "SwapFinished")
            .emit(Flashloan, "SentProfit");
        const balance = await USDT.balanceOf(owner.address);
        expect(balance.gt(getBigNumber(0, 6))).to.be.true;
    });

Do you know why this isn't included in the live script?

[yuichiroaoki]

Good point! That would be awesome. I will do that. Probably that could be done with ethers.js.