LykosAI/StabilityMatrix · error · ProcessException

pip show failed with code

Error message

pip show failed with code {result.ExitCode}: {result.StandardOutput}, {result.StandardError}

What it means

UvVenvRunner.PipShow runs `uv pip show <package>` against the venv and throws this ProcessException when the process exits with a non-zero code and the output does not contain the handled "Package(s) not found" marker. It wraps the pip/uv subprocess failure (including its stdout and stderr) so callers get the underlying pip diagnostics instead of a raw exit code. It means the query itself failed — e.g. uv could not talk to the environment — not merely that the package is absent.

Solutions

1. Read the StandardOutput/StandardError embedded in the message to identify the underlying pip/uv failure and fix that cause.
2. Verify the venv is intact: check that PythonPath exists and `uv pip show` runs manually against the same interpreter.
3. Recreate the venv (e.g. UvVenvRunner.SetupUvVenv / delete and re-setup) if the interpreter or site-packages are broken.
4. Confirm the uv executable version matches expectations (File.Exists(UvExecutablePath) passed, but the binary may be stale) and update it.

Example fix

// before: assuming null means 'not installed' for every failure
var info = await runner.PipShow(packageName);
// after: catch and distinguish 'not installed' (null) from a real pip failure
PipShowResult? info;
try { info = await runner.PipShow(packageName); }
catch (ProcessException ex) {
    Logger.Error($"pip show failed for {packageName}: {ex.Message}");
    throw; // not-found is returned as null by PipShow; this is a genuine failure
}

if (!File.Exists(runner.UvExecutablePath)) throw new InvalidOperationException("uv missing");
if (!File.Exists(runner.PythonPath)) throw new InvalidOperationException("venv python missing");

static bool VenvUsable(UvVenvRunner r) => File.Exists(r.UvExecutablePath) && File.Exists(r.PythonPath);

try { var info = await runner.PipShow(pkg); }
catch (ProcessException ex) { Logger.Error(ex.Message); throw; } // null already means 'not installed'

When it happens

Trigger: Calling UvVenvRunner.PipShow(packageName) where `uv pip show --python <venvPython>` exits non-zero for a reason other than "Package(s) not found": a corrupt or missing venv python, an invalid/unreachable --index/--python configuration, or uv crashing before producing a show result.

Common situations: The venv's python interpreter was deleted or upgraded out from under the venv; the uv executable is a mismatched version; environment variables or a custom index passed to the runner break the command; disk/permission problems inside the venv cause pip internals to fail.

Related errors

• Venv creation failed with code
• pip install failed with code
• pip list failed with code
• Venv creation failed with code
• pip install failed with code

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/7becda0ac4afadfd. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Core/Python/UvVenvRunner.cs:394

                EnvironmentVariables
            )
            .ConfigureAwait(false);

        var packageNotFound =
            result.StandardOutput?.Contains("Package(s) not found", StringComparison.OrdinalIgnoreCase)
                == true
            || result.StandardError?.Contains("Package(s) not found", StringComparison.OrdinalIgnoreCase)
                == true;

        if (packageNotFound)
        {
            return null;
        }

        // Check return code
        if (result.ExitCode != 0)
        {
            throw new ProcessException(
                $"pip show failed with code {result.ExitCode}: {result.StandardOutput}, {result.StandardError}"
            );
        }

        if (string.IsNullOrWhiteSpace(result.StandardOutput))
        {
            throw new ProcessException(
                $"pip show returned no output for package '{packageName}': {result.StandardError}"
            );
        }

        return PipShowResult.Parse(result.StandardOutput);
    }

    /// <summary>
    /// Run a pip index command, return result as PipIndexResult.
    /// </summary>
    public async Task<PipIndexResult?> PipIndex(

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