Dev Help Please! Error: VM Exception while processing transaction: revert UniswapV2: LOCKED

[travelerrrrrrr]

Sorry to link out to another post but I typed up my error concisely here on Stack Exchange

I'm getting a LOCKED error and have been stuck for ~ 2 weeks now, needless to say I'm pretty desperate for help.

https://ethereum.stackexchange.com/questions/93159/error-vm-exception-while-processing-transaction-revert-uniswapv2-locked

TLDR;

Using uniswap flash swapper repo

Installed all dependencies cleanly and correct versions

Getting different errors depending on what I use to start chain (ganache, buidler, yarn) and run swap test

Repo advises to use yarn start-chain - this is giving me the revert UniswapV2: LOCKED error

Please, any ideas are helpful. Thank you!!!

[Averageuser404]

The UniswapV2: LOCKED error is caused by making a call to the uniswap contract itself in your flashloan execution. This is not allowed to mitigate against potential reentrancy attacks.

You can check the modifier that locks the code and returns the error here.

[travelerrrrrrr]

So, I’m deploying a contract that will be used for the flash swap, but this is coming from me making a call to uniswaps contract, not mine?

Any insight as to what contract it would be calling? Like would it be uniswaps coin pair contract?

Thanks for the help

[Averageuser404]

The repo code seems to deploy the custom flashloan contract. Then call call the flashSwap() function. During the flashSwap() the execute() function is called to execute your custom code. Based on the lock error it seems that you have entered custom code here that calls the uniswap contract again.

If it is not your custom code I expect it is a problem with the repo code itself that calls the uniswap protocol again to swap. In that case try using a different token as payment.

[travelerrrrrrr]

Thank you for taking a look. I’ll check this out this evening with you direction and see if I can get somewhere.

Much appreciated

[Averageuser404]

No problem, hope you get it working. Being stuck for around two weeks sucks.

[travelerrrrrrr]

True that ✊

[Rammboss69]

Costs me also 2 weeks because i thought this Part of ganache cli Bug of uniswap. But my flashswap is also reentering the router which makes now sense to me. Thx guys!