launcher-os

A NixOS flake that builds a Hyprland + DankMaterialShell workstation. nixos-rebuild switch is the only way anything gets installed, which is the entire point: editing the manifest is the install mechanism, so it can never drift from the running machine.

This replaced an Arch/pacman bash installer. The reasoning, and the evidence that the old manifests had stopped matching reality, is in digital-brain/05-nixos-migration.md.

Layer ownership

The seam that matters. Two tools, no overlap:

Layer	Owner
System, hardware, services, packages	this flake
$HOME dotfiles	chezmoi, from a separate repo

home-manager is a deliberate non-goal — chezmoi already owns $HOME, works on macOS too, and is not what was broken. Same for mise, which still manages language toolchains.

Layout

Path	Contents
flake.nix	Inputs, the madthinkpad host, the install and check apps
modules/	The launcher-os.* options every host composes
hosts/<name>/	Per-machine hardware, disk layout, option switches
pkgs/	Scripts packaged with writeShellApplication (los, the installer, the gates)
default/hypr/	Hyprland config delivered to /etc/launcher-os/hypr, read by chezmoi's hyprland.lua
digital-brain/	Design notes and install runbooks
install/	Superseded. The old Arch bootstrap; nothing here runs it (see below)

Hosts turn on what they need:

launcher-os = {
  user = "dpickett";
  desktop.enable = true;   # Hyprland, DMS, greeter, portals
  dev.enable = true;       # docker, postgres, nix-ld for mise toolchains
  apps.enable = true;      # desktop applications
  printing.enable = true;  # printing and scanning
  laptop.enable = true;    # TLP power management
};

The base layer — networking, pipewire, bluetooth, fonts, the shell, CLI tooling — is unconditional.

Inputs

The stable base is nixos-26.05. The desktop stack floats, and each fast-moving input keeps its own nixpkgs on purpose: making them follow the stable base is a documented cause of Hyprland build failures and cache misses. hyprland, dms, vicinae and handy are all pinned this way, with Hyprland's own mesa used for hardware.graphics so GL does not break on a version mismatch.

Installing a machine

Full runbook, including the USB stick and the BIOS settings: digital-brain/06-madthinkpad-install.md. It reformats the whole disk. From a booted NixOS minimal ISO:

sudo nix --extra-experimental-features "nix-command flakes" \
  run github:LaunchWare/launcher-os#install -- madthinkpad

It shows the target disk and waits for you to type the hostname before wiping anything. After the first login:

los bootstrap https://github.com/dpickett/dotfiles.git

Day to day

los switch     # nixos-rebuild switch for this host, then chezmoi apply

los finds the flake at ~/work/launcher-os; override with LAUNCHER_OS_FLAKE. Rolling back is a previous generation in the systemd-boot menu.

Checks

One command is the whole gate, and the git hooks and CI both run it:

nix run .#check            # nixfmt, deadnix, statix, shellcheck, actionlint, lua syntax
nix run .#check -- --full  # the above, plus evaluating every host
nix fmt                    # format the nix sources

Enable the hooks once per clone:

git config core.hooksPath .githooks

pre-commit runs the file gates against the index (~2s); pre-push adds host evaluation (~30s, and nix caches none of it, which is why it is not on every commit).

CI runs the same nix run .#check -- --full plus nix flake check, so the hooks and the workflow cannot drift into disagreeing about what conforms. CI stops at evaluation on purpose — the madthinkpad closure is around 23.5 GiB against roughly 14 GiB of disk on a GitHub-hosted runner, so the build belongs on the machine that is going to boot it.

The Arch installer

install/ is the pre-NixOS bootstrap: pacman, paru, AUR helpers, and packages/*.txt manifests. Nothing in the flake references it and none of it runs on NixOS. It is kept only as a record of what the old setup installed while the last of it gets ported, and is linted but not otherwise maintained. pkgs/install.sh is the current installer and is unrelated to it.

Some notes under digital-brain/ predate the migration too — 01-tool-specifications.md still describes Waybar, Walker and Mako, which DMS and Vicinae replaced.