libkrun-builder

Lightweight krunkit-based Linux builder for Apple Silicon.

Overview

libkrun-builder provisions and manages a NixOS virtual machine on macOS using krunkit (libkrun). It provides a fast Linux build environment for Apple Silicon Macs, enabling native aarch64-linux Nix builds without emulation. The VM image is built from upstream nixpkgs to maximize binary cache hits, and configuration is layered via YAML files and environment variables (using figment).

Usage

# Build the CLI tool
nix build

# Build the NixOS guest disk image
nix build .#nixosConfigurations.guest.config.system.build.diskImage

# Use as a nix-darwin module
{
  imports = [ libkrun-builder.darwinModules.default ];
}

Configuration

Config is loaded from /etc/libkrun-builder/config.yaml (or $LIBKRUN_CONFIG), with environment variable overrides using the LIBKRUN_ prefix.

image: /path/to/nixos-guest.qcow2
workdir: /var/lib/libkrun-builder
cores: 6
memory: 8GiB
ssh_port: 31122

License

MIT