Unchecked return value not flagged

[gsalzer]

Description

Mythril does not detect an unchecked call return value.

How to Reproduce

$ cat ucrv.sol
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;
contract ucrv {
  function send(address payable a) public {
    a.send(1);
  }
}
$ ./myth version # repo cloned, pip install -r requirements
Mythril version v0.24.5
$ ./myth analyze ucrv.sol
The analysis was completed successfully. No issues were detected.

Expected behavior

Mythril reports an unchecked return value.

Environment

• Mythril version: 0.24.5
• Python version: 3.10.12
• OS and Version: GNU/Linux 6.5.0-21 Ubuntu 22.04.1 x86_64

Additional Environment or Context

The call to the solver in mythril/analysis/module/modules/unchecked_retval.py, line 87 seems to throw UnsatError, which I wouldn't have expected.