[Copilot]

Tests (MacOS) was failing in taco-smt-encoder despite cvc5 being installed, because version discovery only parsed stdout while the Homebrew cask path can emit --version output on stderr. This updates solver version detection to accept either stream without changing solver-selection semantics.

• Root cause

  • get_smt_solver_version treated missing parseable stdout as failure, even when stderr contained a valid version string.

• Implementation

  • Added parse_smt_solver_version_output(stdout, stderr) to parse version from both streams.
  • Updated get_smt_solver_version to:
    • return success when either stream yields a valid version,
    • preserve existing NotInstalled behavior when execution fails and no version is parseable,
    • otherwise return ParseVersionError.

• Coverage

  • Added a focused unit test for stderr-based version parsing (test_parse_version_from_stderr) to lock behavior for cvc5/macOS-style output.

if let Ok(version) = parse_smt_solver_version_output(&out.stdout, &out.stderr) {
    return Ok(version);
}