Desktop (Nixarchy / Omarchy on Hyprland)

Last Updated: 2026-09-01

The problem

This fleet went through five Wayland compositors — niri, labwc, mango, Hyprland and COSMIC — plus two shells (Noctalia, DankMaterialShell) and three greeters. Every one of them needed its own portal wiring, its own theme plumbing and its own session entry, and each combination broke in a different way. Screen sharing in particular fails silently whenever XDG_CURRENT_DESKTOP disagrees with the portal backend actually installed.

The solution

One Wayland session, on every host: Omarchy on Hyprland, packaged for NixOS as Nixarchy and consumed as a flake input. GNOME stays installed and selectable as a fallback. Everything else is gone, including the flake inputs.

Host	Sessions offered	Greeter	Default session
p620	omarchy, gnome	SDDM (Omarchy's)	omarchy
razer	omarchy, gnome	SDDM (Omarchy's)	omarchy
p510	omarchy, gnome	SDDM (Omarchy's)	omarchy

Each host wires it up in hosts/<host>/nixos/nixarchy.nix, which imports the Nixarchy module plus a set of shared fragments from hosts/common/nixos/:

imports = [
  inputs.nixarchy.nixosModules.nixarchy
  ../../../nixarchy-apps.nix            # app selection, copied in by nixarchy-apply
  ../../common/nixos/omarchy-input.nix
  ../../common/nixos/omarchy-sddm.nix
  ../../common/nixos/omarchy-workspaces.nix
  ../../common/nixos/omarchy-gog.nix
  ../../common/nixos/omarchy-sole-hyprland.nix
  ../../common/nixos/omarchy-stylix-theme.nix
];

programs.nixarchy.enable = true;
programs.nixarchy.user = "olafkfreund";   # puts the user in the `input` group
programs.nixarchy.displayManager = true;  # Omarchy's SDDM
programs.nixarchy.bootSplash = "force";   # Omarchy's Plymouth theme

Why two files sit at the flake root

A flake cannot read a file outside its own tree. Two Omarchy features therefore write into the repository itself, and both leave the tree dirty — which matters, because nhs refuses to run on a dirty tree.

File	Written by	Read by
nixarchy-apps.nix	nixarchy-apply (copies ~/.config/nixarchy/apps.nix)	each host's nixarchy.nix
nixarchy-theme.nix	the theme-set.d hook of omarchy theme set X	modules/desktop/stylix-theme.nix

Copying is not importing

nixarchy-apply copies apps.nix in and stops there. Importing it is the host's job. p620 lacked that import until recently, so app selections made in the menu were copied into the flake and built by nobody.

Only one Hyprland entry at login

programs.hyprland is enabled by the Nixarchy module itself, not by this repo. It supplies the portal, uwsm and the wayland-session basics, so it cannot simply be turned off — but it also registers its own Hyprland login entry, giving two indistinguishable choices at the greeter.

There is no option to drop a single session. hosts/common/nixos/omarchy-sole-hyprland.nix therefore forces the module off and restates the parts Nixarchy needs. Read that file before touching anything Hyprland-adjacent; the two obvious workarounds both fail:

• A filtered mkForce on services.displayManager.sessionPackages would have to read the value it defines — infinite recursion.
• A session-less repackage of the compositor is rejected by the option's own type, which asserts providedSessions != [ ].

The nix eval diff of the whole system config before and after that file is empty apart from sessionPackages.

Configuration is Lua, not hyprlang

Hyprland 0.56 config on these hosts is Lua. Dispatchers are namespaced under hl.dsp.*, so the string forms found in most documentation silently do nothing:

hyprctl dispatch 'hl.dsp.dpms({ action = "enable" })'   # correct
hyprctl dispatch "dpms on"                              # no-op here

User-facing config lives in ~/.config/hypr/ (hyprland.lua, input.lua, monitors.lua, bindings.lua), seeded by Nixarchy with cp -rn. Because the seed does not overwrite, a Home Manager file competing for the same path needs force = true.

Theming: Omarchy is the source of truth

omarchy theme set X retints the 24 files Omarchy owns immediately and writes X into nixarchy-theme.nix. modules/desktop/stylix-theme.nix reads that name, loads the theme's colors.toml out of the Nixarchy package, maps its named roles onto base16 and hands the result to Stylix.

Everything Omarchy cannot reach at runtime — Plymouth, GRUB, the console, GTK, Qt, fonts and the Home Manager targets — follows at the next rebuild, not instantly. Because inputs.nixarchy is flake-wide, p510 follows the same palette as the workstations.

Reach the package through inputs

Use inputs.nixarchy, never config.programs.nixarchy.package. Nixarchy consumes Stylix, so reading its config from the module that defines stylix.base16Scheme closes the module fixpoint and evaluation dies with infinite recursion.

See Theming (Stylix) for the palette itself.

Screen sharing

xdg.portal.configPackages carries hyprland-portals.conf, which routes ScreenCast to the Hyprland backend rather than wlr. Losing it is the classic screen-sharing failure on this fleet, so omarchy-sole-hyprland.nix names it explicitly rather than relying on a default.

If a cast fails with "unit is masked", the cause is almost always a stale XDG_CURRENT_DESKTOP from switching sessions without a clean re-login.

What was removed

niri, labwc, mango, Noctalia and DankMaterialShell — modules, sessions, greeters and flake inputs. Any comment or document describing dms-shell.nix, "Niri (DMS)", "Hyprland (DMS)" or ${DESK_SHELL:-noctalia} is describing a tree that no longer exists.

COSMIC is parked, not removed: desktop.cosmic.enable = false on every host, with the module at modules/desktop/cosmic.nix and the applets under pkgs/cosmic-applets/ kept for an easy re-enable.