the oyente can not find issue

[zxhubo]

I have been write a test contract,the code is

pragma solidity ^0.4.23;

contract Test{

    function t() returns (uint8){
        
        uint8 a = 255;
        uint8 b = 1;
        return a+b;
        
    }

}

then ,I installed oyente by docker,and run command :python oyente.py -s Test.sol. but the result is that this is no issue ; root@c5571baca9e7:/oyente/oyente# python oyente.py -s Test.sol WARNING:root:You are using evm version 1.8.2. The supported version is 1.7.3 WARNING:root:You are using solc version 0.4.21, The latest supported version is 0.4.19 INFO:root:contract Test.sol:Test: INFO:symExec: ============ Results =========== INFO:symExec: EVM Code Coverage: 98.7% INFO:symExec: Integer Underflow: False INFO:symExec: Integer Overflow: False INFO:symExec: Parity Multisig Bug 2: False INFO:symExec: Callstack Depth Attack Vulnerability: False INFO:symExec: Transaction-Ordering Dependence (TOD): False INFO:symExec: Timestamp Dependency: False INFO:symExec: Re-Entrancy Vulnerability: False INFO:symExec: ====== Analysis Completed ======

but this test contract have a overflow issue, why the oyent cann't find this issue.

[0xHaas]

The warning is transparent as to why: WARNING:root:You are using solc version 0.4.21, The latest supported version is 0.4.19

The version of Solidity you're trying to analyze is not supported, thus appropriate checks (such as detecting the overflow) are not present.

[JsHuang]

because both var a and b are real ,so no integer overflow will occur.