LykosAI/StabilityMatrix · error · NotSupportedException

Nunchaku is not supported on macOS or GPUs with compute…

Error message

Nunchaku is not supported on macOS or GPUs with compute capability < 7.5.

What it means

InstallNunchakuStep.ExecuteAsync throws NotSupportedException when installing Nunchaku on macOS or when the selected GPU's compute capability is null or below 7.5 (Turing). Nunchaku wheels only exist for CUDA GPUs with sm >= 7.5.

Solutions

1. Install on a Windows/Linux machine with an NVIDIA GPU of compute capability >= 7.5 (Turing or newer)
2. Ensure a GPU is detected so PreferredGpu.ComputeCapabilityValue is set
3. Skip the Nunchaku install step and run the package without it

Example fix

// before
await step.ExecuteAsync();
// after
if (!Compat.IsMacOS && gpu?.ComputeCapabilityValue is >= 7.5m) await step.ExecuteAsync(); else /* skip */

if (Compat.IsMacOS || gpu?.ComputeCapabilityValue is null or < 7.5m) skipNunchaku();

bool CanInstallNunchaku(GpuInfo gpu) => !Compat.IsMacOS && gpu.ComputeCapabilityValue is >= 7.5m;

try { await step.ExecuteAsync(progress); } catch (NotSupportedException) { /* skip nunchaku, continue install */ }

When it happens

Trigger: Running the Nunchaku install step with Compat.IsMacOS true, or PreferredGpu unset (ComputeCapabilityValue null), or a pre-Turing GPU (e.g. GTX 10-series Pascal, compute 6.1).

Common situations: Apple Silicon users attempting Nunchaku install; users with older NVIDIA GPUs; PreferredGpu not detected so capability is null.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• Windows ROCm package commands are only supported on Windows.
• Service type is not assignable to
• Service of type is not registered for
• Recycle bin is not available on this platform
• Sampler not selected

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/c7b6462f9989819a. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Core/Models/PackageModification/InstallNunchakuStep.cs:23

using StabilityMatrix.Core.Models.Packages.Extensions;
using StabilityMatrix.Core.Models.Progress;
using StabilityMatrix.Core.Python;

namespace StabilityMatrix.Core.Models.PackageModification;

public class InstallNunchakuStep(IPyInstallationManager pyInstallationManager) : IPackageStep
{
    public required InstalledPackage InstalledPackage { get; init; }
    public required DirectoryPath WorkingDirectory { get; init; }
    public required GpuInfo? PreferredGpu { get; init; }
    public required IPackageExtensionManager ComfyExtensionManager { get; init; }
    public IReadOnlyDictionary<string, string>? EnvironmentVariables { get; init; }

    public async Task ExecuteAsync(IProgress<ProgressReport>? progress = null)
    {
        if (Compat.IsMacOS || PreferredGpu?.ComputeCapabilityValue is null or < 7.5m)
        {
            throw new NotSupportedException(
                "Nunchaku is not supported on macOS or GPUs with compute capability < 7.5."
            );
        }

        var venvDir = WorkingDirectory.JoinDir("venv");
        var pyVersion = PyVersion.Parse(InstalledPackage.PythonVersion);
        if (pyVersion.StringValue == "0.0.0")
        {
            pyVersion = PyInstallationManager.Python_3_10_11;
        }

        var baseInstall = !string.IsNullOrWhiteSpace(InstalledPackage.PythonVersion)
            ? new PyBaseInstall(
                await pyInstallationManager.GetInstallationAsync(pyVersion).ConfigureAwait(false)
            )
            : PyBaseInstall.Default;

        await using var venvRunner = baseInstall.CreateVenvRunner(

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