ian-nix

A reproducible macOS configuration built on Nix: a bootstrap script to install Nix, plus a flake that declares the whole machine (system settings, user environment, and Homebrew) with nix-darwin, home-manager, and nix-homebrew.

Layout

Path	Purpose
ensure-nix.sh	Idempotent bootstrap: install Nix, enable flakes, set git identity.
configure-darwin.sh	Apply the flake (darwin-rebuild switch); also build / check.
flake.nix	Entry point: builds darwinConfigurations.<hostname> from ./darwin.
darwin/	System (nix-darwin) modules — default.nix, homebrew.nix.
home/	User (home-manager) modules — default.nix, packages.nix, shell.nix, git.nix, vscode.nix.

What's managed

Area	What	Where
Nix	flakes + nix-command enabled	darwin/default.nix
CLI tools (nixpkgs, pinned)	ripgrep, fd, jq, btop, dust, tldr, awscli2, cloudflared, stripe-cli, temporal-cli, uv, nodejs_24, pnpm_10, python3	home/packages.nix
Homebrew brews	colima, docker, docker-compose (container tooling)	darwin/homebrew.nix
Homebrew casks	claude-code, codex, linearmouse, ngrok, slack, visual-studio-code	darwin/homebrew.nix
Shell	zsh, starship, atuin, zoxide, fzf, eza, bat, direnv, lazygit, gh	home/shell.nix
Git	push.default, merge.conflictstyle, delta pager (identity set by ensure-nix.sh)	home/git.nix
VSCode	settings.json (read-only); baseline extensions seeded but UI-editable	home/vscode.nix

Node comes from nodejs_24 (nixpkgs), pinned by the flake. Per-project flake dev shells can provide other versions.

Quick start

# 1. Install Nix (idempotent, safe to re-run).
./ensure-nix.sh

# 2. Edit the placeholders at the top of flake.nix: username, hostname, system.
#    Defaults for this machine are pre-filled.

# 3. (Optional) preview without touching the system.
./configure-darwin.sh build

# 4. Build and activate. The first run bootstraps darwin-rebuild; later runs use
#    it directly. Re-run after editing the configuration.
./configure-darwin.sh

configure-darwin.sh stages the flake files (flakes ignore untracked files), then runs darwin-rebuild switch against darwinConfigurations.<LocalHostName>. Override the target with FLAKE_HOST=….

After the first switch, experimental-features is owned declaratively by darwin/default.nix, making the nix.conf line written by ensure-nix.sh redundant (harmless to leave). Editing files under darwin/ or home/ and re-running ./configure-darwin.sh converges the machine to match, on this Mac or any other.

Note

The script auto-stages with git add (it never commits). When running commands manually, note that flakes only see git-tracked files; git add after creating or renaming any .nix file.

ensure-nix.sh

Ensures the Nix package manager is installed on macOS with flakes enabled. Idempotent and safe to run repeatedly: it converges to the same state without repeating work or duplicating config.

Usage

./ensure-nix.sh

The installer requires administrator privileges and may prompt for a password (sudo).

What it does

• Verifies it is running on macOS (works on both Apple Silicon and Intel).
• Sources the Nix profile scripts, then checks whether nix actually works (runs it, not just a PATH lookup); if so, prints the version and installs nothing.
• On a clean machine, installs Nix via the official installer in --daemon (multi-user) mode, the recommended setup on macOS, and loads the new environment so nix is usable in the same shell.
• If it finds Nix files under /nix but nix is not working (a partial or broken install), it stops with repair instructions rather than re-running the installer over a dirty store, so a re-run never makes things worse.
• Enables nix-command and flakes in ~/.config/nix/nix.conf, but only if they are not already on. It inspects the effective (last-wins) experimental-features setting, so re-running never duplicates the line.

Configuration

Override these environment variables to customize the install:

Variable	Default	Description
NIX_INSTALLER_URL	https://nixos.org/nix/install	Installer script URL.
NIX_INSTALL_ARGS	--daemon	Extra args passed to the installer.
ENABLE_FLAKES	1	Enable nix-command + flakes in nix.conf; set 0 to skip.

For example, to use the Determinate Systems installer instead:

NIX_INSTALLER_URL=https://install.determinate.systems/nix \
NIX_INSTALL_ARGS="install --no-confirm" ./ensure-nix.sh

Requirements

• macOS
• curl (ships with macOS)