Darwin Package Management Strategy¶

Overview¶

This document outlines the recommended package management strategy for nix-darwin systems, balancing the benefits of Nix's declarative approach with the practical realities of macOS.

Key Principle: Declarative Everything¶

The homebrew.onActivation.cleanup = "zap" setting enforces strict declarative management. This is a feature, not a bug - it ensures your system exactly matches your configuration.

Package Management Rules¶

Use Nix for:¶

All CLI tools and utilities (ripgrep, sops, go-task, etc.)
Development languages and toolchains (Python, Node.js, Go, Rust)
System utilities and infrastructure tools (terraform, kubectl, helm)
Text editors and development environments (vim, emacs, neovim)

Use Homebrew (declared in Nix) for:¶

GUI applications (Discord, Slack, Obsidian, etc.)
macOS-specific commercial software (TablePlus, Transmit)
Tools that don't work well in Nix (certain macOS-only utilities)

Implementation¶

1. Daily Driver Tools¶

For tools you use regularly, add them to the appropriate home-manager module:

# home/_modules/shell/utilities/default.nix
home.packages = with pkgs; [
  ripgrep
  sops
  go-task
  # ... other daily tools
];

2. Development Languages¶

For language toolchains you use regularly:

# home/_modules/development/languages/default.nix
home.packages = with pkgs; [
  python311
  nodejs
  go
  rustup
  # ... other languages
];

3. GUI Applications¶

Declare all GUI apps in your homebrew configuration:

# modules/darwin/homebrew.nix or hosts/rymac/default.nix
homebrew.casks = [
  "discord"
  "slack"
  "obsidian"
  # ... other GUI apps
];

Migration Process¶

Before making changes, run: brew list --formula > ~/current-brew-formulae.txt
Add desired packages to your Nix configuration
Validate with: nix flake check
Build with: darwin-rebuild build --flake .
Apply with: darwin-rebuild switch --flake .

Handling Edge Cases¶

Packages not in nixpkgs¶

For tools like talhelper that aren't in nixpkgs: 1. Check if there's a flake input available 2. Create a custom package (see pkgs/ directory for examples) 3. As a last resort, add to homebrew.brews

Darwin-only packages¶

Use conditional imports for Darwin-specific tools:

home.packages = with pkgs; [
  # Cross-platform tools
  ripgrep
  sops
] ++ lib.optionals pkgs.stdenv.isDarwin [
  mas  # Mac App Store CLI
];

Benefits of This Approach¶

Reproducibility: Your entire system can be rebuilt from configuration
Version Control: All changes are tracked in git
No Surprises: System always matches configuration
Easy Rollbacks: Previous generations are preserved
Team Sharing: Colleagues can replicate your exact environment

Common Commands¶

# Check what's currently installed via Homebrew
brew list --formula
brew list --cask

# Validate configuration
nix flake check

# Build without applying (safe preview)
darwin-rebuild build --flake .

# Apply configuration
darwin-rebuild switch --flake .

# Rollback to previous generation
darwin-rebuild rollback