LykosAI/StabilityMatrix · error · ProcessException

pip install failed with code

Error message

pip install failed with code {Process.ExitCode}: {output.ToString().ToRepr()}

What it means

PipInstall() runs `-m pip install --exists-action s` and throws ProcessException when the pip process exits non-zero. The exception message includes the exit code and captured output (via ToRepr) to surface pip's own error (resolution conflict, network failure, missing package, etc.).

Solutions

1. Read the captured output in the exception message to find pip's specific failure line.
2. Check network/proxy access to the package index; configure PipIndex if using a mirror.
3. Relax or correct the pinned versions in the requirements causing resolution failures.
4. Re-run pip install manually inside the venv to reproduce and iterate on the error.

Example fix

// before
await venvRunner.PipInstall("torch==99.0");
// after
try
{
    await venvRunner.PipInstall("torch>=2.0");
}
catch (ProcessException e)
{
    Logger.Error("pip install failed: {Msg}", e.Message);
    throw;
}

try
{
    await venvRunner.PipInstall(args, onOutput);
}
catch (ProcessException e)
{
    Logger.Error("pip install failed: {Msg}", e.Message); // message carries pip output
    throw;
}

When it happens

Trigger: Any pip install failure: package/version not found on the index, dependency resolution conflict, network/proxy failure, missing compiler for an sdist build, or disk full — anything making `pip install` return non-zero.

Common situations: Version specifier not available for the platform/Python version; private index not configured (PipIndex); corporate proxy blocking PyPI; build tools missing on Windows for packages without wheels; stale hash/requirements pinning.

Related errors

• pip install failed with code
• pip list failed with code
• pip show failed with code
• pip show returned no output for package
• get-pip not found

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/38a401e0f84237a3. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Core/Python/PyVenvRunner.cs:249

        // Record output for errors
        var output = new StringBuilder();

        var outputAction = new Action<ProcessOutput>(s =>
        {
            Logger.Debug($"Pip output: {s.Text}");
            // Record to output
            output.Append(s.Text);
            // Forward to callback
            outputDataReceived?.Invoke(s);
        });

        RunDetached(args.Prepend("-m pip install").Concat("--exists-action s"), outputAction);
        await Process.WaitForExitAsync().ConfigureAwait(false);

        // Check return code
        if (Process.ExitCode != 0)
        {
            throw new ProcessException(
                $"pip install failed with code {Process.ExitCode}: {output.ToString().ToRepr()}"
            );
        }
    }

    /// <summary>
    /// Run a pip uninstall command. Waits for the process to exit.
    /// workingDirectory defaults to RootPath.
    /// </summary>
    public async Task PipUninstall(ProcessArgs args, Action<ProcessOutput>? outputDataReceived = null)
    {
        if (!File.Exists(PipPath))
        {
            throw new FileNotFoundException("pip not found", PipPath);
        }

        // Record output for errors
        var output = new StringBuilder();

View on GitHub (pinned to af93d6ef57)