nixos-config

• Nix (install through Determinate Systems) with flakes enabled
• macOS on Apple Silicon (aarch64-darwin)

After editing configuration under hosts/, modules/, or overlays/:

1. Build and switch (most common):

   nix run .#build-switch

2. Build only (validate changes without activating):

   nix run .#build

   This compiles the system closure and removes the ./result symlink when done. Nothing is activated.

Flake inputs (nixpkgs, darwin, home-manager, Homebrew taps, etc.) are pinned in flake.lock. To refresh them:

# Update all inputs
nix flake update

After updating, rebuild and switch. Review flake.lock changes before committing if you track this repo in git.

List available system generations:

sudo darwin-rebuild --list-generations

Roll back interactively (prompts for a generation number):

nix run .#rollback

Remove system generations older than 7 days and collect unreachable store paths:

nix run .#clean

Home Manager and nix-darwin keep their own generation history; darwin-rebuild --list-generations shows system-level generations.

Although declarative nix is great, there are few things that are not managed through nix:

• cursor agent cli
• GitHub Desktop
• mise global config (e.g., output of mise use --global)
• AstroNvim's plugins (see "Neovim (AstroNvim)" below)
• Enabling the 1Password SSH Agent (Settings > Developer > "Use the SSH Agent" in the 1Password app), required once per machine for SSH-based git commit signing (see modules/shared/home-manager.nix)

AstroNvim is installed as a set of dotfiles rather than a Nix package, since it's fundamentally a Lua config that expects to manage its own plugins. Nix and AstroNvim's own tooling split responsibilities:

• Nix-managed:
  • The config itself lives in modules/shared/config/nvim/ (a checked-in copy of the AstroNvim template) and is symlinked to ~/.config/nvim by home-manager via modules/shared/files.nix.
  • neovim plus AstroNvim's CLI dependencies (ripgrep, lazygit, fd, git) live in modules/shared/packages.nix.
  • The Nerd Font (font-jetbrains-mono-nerd-font, used for file icons/statusline) is a Homebrew cask in modules/darwin/casks.nix, wired into Ghostty's font-family in modules/darwin/home-manager.nix.
• Left to AstroNvim's own tooling (pragmatic, not nix-managed):
  • lazy.nvim installs AstroNvim core and all plugins by cloning them from git on first launch, and mason.nvim installs LSPs/formatters/DAPs on demand (:LspInstall, :MasonInstall). Reimplementing this in Nix (e.g. via lazy-nix-helper.nvim) was considered and skipped as unnecessary overhead for this setup.
  • Because ~/.config/nvim is a read-only symlink into the nix store, lazy.nvim's lockfile is redirected to the (writable, non-nix-managed) state dir in lua/lazy_setup.lua (vim.fn.stdpath("state") .. "/lazy-lock.json") instead of its usual home inside the config directory.

To pin plugin versions across machines (the non-Nix equivalent of flake.lock), copy the generated lockfile into the repo and commit it:

cp ~/.local/state/nvim/lazy-lock.json modules/shared/config/nvim/lazy-lock.json

To change the config itself, edit files under modules/shared/config/nvim/ (not the symlinked ~/.config/nvim path directly) and run nix run .#build-switch.