Why is library masking all gas estimation errors as TransactionFailed?

[uhbif19]

Version: 0.1.0b39

eth_tester is masking all errors on gas estimation as TransactionFailed. This does lose information about problem type (revert or opcode problem) and revert message. That is not very convenient for debugging, because developer does not get any information about contract error.

Here is related code:

https://github.com/ethereum/eth-tester/blob/master/eth_tester/backends/pyevm/main.py#L463

What is the reason for such behavior?

[pipermerriam]

It should still be re-raising those exceptions, just with a common exception type. Is that not he behavior you're seeing?

[uhbif19]

I see only reraised TransactionFailed exception, without its reason and revert message. If there is a field, there is an original exception stored, I have not found it.

[pipermerriam]

👍 we should fix this to ensure that this information is properly preserved. Thanks for reporting this.

[pipermerriam]

The fix for this is going to involve removal of the replace_exceptions decorator in favor of explicit exception handling to ensure the exception data is preserved.

[uhbif19]

I could make some PR, if you provide description how this suppose to work and where related tests are located.