type3 tx rejected on Cancun looks valid (INSUFFICIENT_MAX_FEE_PER_BLOB_GAS) about execution-spec-tests

[marioevz]

If you apply the get_blob_gasprice function from the EIP-4844 to the currentExcessBlobGas value, you get 0x02 as the result, the transaction has maxFeePerBlobGas==0x01 which is lower than the minimum value the current environment expects, therefore the transaction is invalid.

[spencer-tb]

Adding here as I wrote it out already :D

From the EIP we have the following formula:

def get_blob_gasprice(header: Header) -> int:
    return fake_exponential(
        MIN_BLOB_GASPRICE,
        header.excess_blob_gas,
        BLOB_GASPRICE_UPDATE_FRACTION
    )

If we utilize currentExcessBlobGas from the env, we end up with a positive value for get_blob_gasprice. As Mario mentioned specifically 0x02.

For the tx to be valid, it must pass this check (from the EIP):

assert tx.max_fee_per_blob_gas >= get_blob_gasprice(block.header)

As "maxFeePerBlobGas" : "0x01" < 0x02, the tx is invalid, with the error: INSUFFICIENT_MAX_FEE_PER_BLOB_GAS.