NixOS + XMonad: Building My Complete Kanagawa Dragon Desktop from Scratch

nix-shell -p git

git clone --single-branch --branch main https://github.com/dennishilk/cthulhu.git "$HOME/cthulhu"

cd "$HOME/cthulhu/WM/xmonad/nixos-kanagawa-dragon"

nix-shell -p git nano

git clone --single-branch --branch main https://github.com/dennishilk/cthulhu.git "$HOME/cthulhu"

cd "$HOME/cthulhu/WM/xmonad/nixos-kanagawa-dragon"

sudo cp -a /etc/nixos "/etc/nixos.before-cthulhu-$(date +%Y%m%d-%H%M%S)"

ls -l /etc/nixos/desktop.nix /etc/nixos/cthulhu-local.nix

sudo cp -n nixos/desktop.nix nixos/cthulhu-local.nix /etc/nixos/

sudo nano /etc/nixos/cthulhu-local.nix

whoami

sudo nano /etc/nixos/configuration.nix

imports = [ ./hardware-configuration.nix ./cthulhu-local.nix ];

less scripts/install-user.sh

bash scripts/install-user.sh

sudo nixos-rebuild build

sudo nixos-rebuild switch

mkdir -p "$HOME/.local/share"

git clone https://github.com/Fausto-Korpsvart/Kanagawa-GKT-Theme.git "$HOME/.local/share/kanagawa-gtk-source"

git -C "$HOME/.local/share/kanagawa-gtk-source" checkout --detach 55ca4ba249eba21f861b9866b71ab41bb8930318

nix-shell -p sassc --run 'bash ~/.local/share/kanagawa-gtk-source/themes/install.sh -n Kanagawa -t green -c dark --tweaks dragon'

xrandr

nano "$HOME/.config/cthulhu/monitors.sh"

mkdir -p "$HOME/Bilder/wallpaper"

cp -n "$HOME/Pictures/my-wallpaper.png" "$HOME/Bilder/wallpaper/1.png"

bash "$HOME/.config/cthulhu/monitors.sh"

sudo systemctl stop display-manager

unset XINITRC

set -e XINITRC

startx

systemctl --user status nixos-fake-graphical-session.target cthulhu-polkit.service

sudo systemctl start display-manager

sudo nano /etc/nixos/cthulhu-local.nix

sudo nixos-rebuild build

sudo nixos-rebuild switch

sudo reboot

cat /etc/X11/xinit/xinitrc

xmonad --recompile && xmonad --restart

wpctl status

fastfetch --logo none

code --install-extension metaphore.kanagawa-vscode-color-theme

code --install-extension PKief.material-icon-theme

{ config, lib, pkgs, ... }:
let cfg = config.cthulhu.desktop;
in {
  options.cthulhu.desktop = {
    enable = lib.mkEnableOption "the Cthulhu Kanagawa Dragon X11 desktop";
    user = lib.mkOption {
      type = lib.types.str;
      description = "An existing normal login account; this module does not create accounts.";
    };
    keyboardLayout = lib.mkOption { type = lib.types.str; default = "de"; };
    standalone = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Explicitly disable Plasma/SDDM after testing startx from a TTY.";
    };
    personalApps = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Install Chrome, VS Code, OBS, Kdenlive and media tools; allows unfree software.";
    };
    gaming = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = "Install Steam/Lutris and 32-bit graphics/audio support; allows unfree software.";
    };
  };
  config = lib.mkIf cfg.enable (lib.mkMerge [ {
    assertions = [ {
      assertion = cfg.user != "YOUR_LOGIN" && config.users.users.${cfg.user}.isNormalUser;
      message = "Set cthulhu.desktop.user to an existing normal account from your installation.";
    } ];
    services.xserver = {
      enable = true;
      xkb.layout = cfg.keyboardLayout;
      desktopManager.xterm.enable = false;
      windowManager.xmonad = {
        enable = true;
        enableContribAndExtras = true;
      };
      displayManager.startx = {
        enable = true;
        generateScript = true;
        extraCommands = ''
          export XDG_CURRENT_DESKTOP=XMonad
          export XDG_SESSION_DESKTOP=xmonad
          export XDG_SESSION_TYPE=x11
          dbus-update-activation-environment --systemd DISPLAY XAUTHORITY \
            XDG_CURRENT_DESKTOP XDG_SESSION_DESKTOP XDG_SESSION_TYPE
        '';
      };
    };
    programs.fish.enable = true;
    users.users.${cfg.user}.shell = pkgs.fish;
    environment.sessionVariables = {
      XCURSOR_THEME = "Bibata-Modern-Classic";
      XCURSOR_SIZE = "24";
    };
    hardware.graphics.enable = true;
    services.pipewire = {
      enable = true;
      alsa.enable = true;
      pulse.enable = true;
      wireplumber.enable = true;
    };
    services.pulseaudio.enable = lib.mkForce false;
    security.rtkit.enable = true;
    services.dbus.enable = true;
    services.udisks2.enable = true;
    services.gvfs.enable = true;
    security.polkit.enable = true;
    systemd.user.services.cthulhu-polkit = {
      description = "Polkit agent for the generated startx session";
      wantedBy = [ "nixos-fake-graphical-session.target" ];
      partOf = [ "nixos-fake-graphical-session.target" ];
      serviceConfig = {
        ExecStart = "${pkgs.polkit_gnome}/libexec/polkit-gnome-authentication-agent-1";
        Restart = "on-failure";
      };
    };
    programs.thunar.enable = true;
    services.tumbler.enable = true;
    xdg.portal = {
      enable = true;
      extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
      config.xmonad.default = [ "gtk" ];
    };
    fonts.fontconfig.enable = true;
    fonts.packages = with pkgs; [
      hack-font nerd-fonts.jetbrains-mono nerd-fonts.fira-code
      noto-fonts noto-fonts-color-emoji
    ];
    environment.systemPackages = with pkgs; [
      bash git curl nano kitty xterm firefox mousepad rofi xmobar dunst
      picom feh xrandr xsetroot maim gsimplecal pavucontrol
      wireplumber libnotify fastfetch bibata-cursors kdePackages.breeze-icons
      sassc gtk-engine-murrine gnome-themes-extra
    ];
  }
  (lib.mkIf cfg.personalApps {
    nixpkgs.config.allowUnfree = true;
    environment.systemPackages = with pkgs; [
      google-chrome vscode obs-studio kdePackages.kdenlive vlc ffmpeg-full
    ];
  })
  (lib.mkIf cfg.gaming {
    nixpkgs.config.allowUnfree = true;
    programs.steam.enable = true;
    hardware.graphics.enable32Bit = true;
    services.pipewire.alsa.support32Bit = true;
    environment.systemPackages = [ pkgs.lutris pkgs.vulkan-tools pkgs.libva-utils ];
  })
  (lib.mkIf cfg.standalone {
    services.desktopManager.plasma6.enable = lib.mkForce false;
    services.displayManager.sddm.enable = lib.mkForce false;
    systemd.defaultUnit = "multi-user.target";
  }) ]);
}

{ ... }: {
  imports = [ ./desktop.nix ];
  cthulhu.desktop = {
    enable = true;
    user = "YOUR_LOGIN"; # Your existing account; do not create a second user.
    keyboardLayout = "de"; # e.g. "us"; keep locale/timezone in configuration.nix.
    standalone = false; # Path A: keep Plasma/SDDM until startx has been tested.
    personalApps = false; # true enables Chrome/Code/OBS/Kdenlive shortcuts.
    gaming = false; # true adds Steam/Lutris and 32-bit support.
  };
}

import XMonad
import Data.List (find)
import Data.Monoid (All(..))
import qualified Data.Map as M
import qualified XMonad.StackSet as W

import XMonad.Actions.AfterDrag (afterDrag)
import XMonad.Actions.Navigation2D (withNavigation2DConfig, windowSwap, Direction2D(..))
import XMonad.Actions.UpdateFocus (focusOnMouseMove, focusUnderPointer)
import XMonad.Hooks.EwmhDesktops (ewmh, ewmhFullscreen)
import XMonad.Hooks.ManageDocks (avoidStruts, docks)
import XMonad.Hooks.ManageHelpers (isDialog)
import XMonad.Layout.MouseResizableTile (mouseResizableTile, mouseResizableTileMirrored)
import XMonad.Layout.Spacing (spacingRaw, Border(..))
import XMonad.Util.EZConfig (additionalKeysP)
import XMonad.Util.SpawnOnce (spawnOnce)

myStartupHook :: X ()
myStartupHook = do
  spawnOnce "bash \"$HOME/.config/cthulhu/monitors.sh\""
  spawnOnce "picom --backend xrender --daemon"
  spawnOnce "dunst"
  spawnOnce "xsetroot -cursor_name left_ptr"
  spawnOnce "xmobar ~/.xmobarrc"

mouseScreenHook :: Event -> X All
mouseScreenHook MotionEvent { ev_x = x, ev_y = y, ev_window = w } = do
  root <- asks theRoot
  if w /= root then pure (All True) else do
    ws <- gets windowset
    let screens = W.current ws : W.visible ws
        inside sc =
          let r = screenRect (W.screenDetail sc)
              px = fromIntegral x :: Int
              py = fromIntegral y :: Int
              left = fromIntegral (rect_x r) :: Int
              top = fromIntegral (rect_y r) :: Int
              right = left + fromIntegral (rect_width r)
              bottom = top + fromIntegral (rect_height r)
          in px >= left && px < right && py >= top && py < bottom
    case find inside screens of
      Just sc | W.screen sc /= W.screen (W.current ws) ->
        windows (W.view (W.tag (W.workspace sc)))
      _ -> pure ()
    pure (All True)
mouseScreenHook _ = pure (All True)

moveToScreenAndTile :: Window -> X ()
moveToScreenAndTile w = do
  d <- asks display
  root <- asks theRoot
  (_, _, _, px, py, _, _, _) <- io $ queryPointer d root
  destination <- pointScreen (fromIntegral px) (fromIntegral py)
  case destination of
    Just sc -> windows (W.sink w . W.shiftWin (W.tag (W.workspace sc)) w)
    Nothing -> windows (W.sink w)

myMouseBindings (XConfig { modMask = modm }) = M.fromList
  [ ((modm, button1), \w -> focus w >> mouseMoveWindow w >> afterDrag (moveToScreenAndTile w))
  , ((modm, button2), \w -> focus w >> windows W.shiftMaster)
  , ((modm, button3), \w -> focus w >> mouseResizeWindow w >> windows W.shiftMaster)
  ]

toggleFloat :: Window -> X ()
toggleFloat w = do
  floating <- gets (W.floating . windowset)
  if M.member w floating
    then windows (W.sink w)
    else windows (W.float w (W.RationalRect 0.15 0.15 0.7 0.7))

main :: IO ()
main = xmonad $ ewmhFullscreen $ ewmh $ withNavigation2DConfig def $ docks $ def
  { modMask     = mod4Mask
  , terminal    = "kitty"
  , borderWidth = 2
  , normalBorderColor = "#393836"
  , focusedBorderColor = "#87a987"
  , startupHook = myStartupHook
  , focusFollowsMouse = True
  , mouseBindings = myMouseBindings
  , rootMask = rootMask def .|. pointerMotionMask
  , handleEventHook = handleEventHook def <+> focusOnMouseMove <+> mouseScreenHook
  , manageHook = manageHook def <+> (isDialog --> doFloat)
  , layoutHook = avoidStruts $ spacingRaw False (Border 8 8 8 8) True (Border 6 6 6 6) True $ (mouseResizableTile ||| mouseResizableTileMirrored ||| Full)
  }
  `additionalKeysP`
  [ ("M-t",        spawn "thunar")
  , ("M-m",        spawn "mousepad")
  , ("M-f", withFocused toggleFloat)
  , ("M-<Left>", focusUnderPointer >> windowSwap L False)
  , ("M-<Right>", focusUnderPointer >> windowSwap R False)
  , ("M-<Return>", spawn "kitty")
  , ("M-q",        kill)
  , ("M-b",        spawn "google-chrome-stable")
  , ("M-o",        spawn "obs")
  , ("M-v",        spawn "code")
  , ("M-d",        spawn "rofi -show drun")
  , ("<Print>", spawn "mkdir -p ~/Bilder/Screenshots && maim -s ~/Bilder/Screenshots/$(date +%Y-%m-%d_%H-%M-%S).png")

  , ("<XF86AudioRaiseVolume>", spawn "$HOME/.local/bin/cthulhu-audio up")
  , ("<XF86AudioLowerVolume>", spawn "$HOME/.local/bin/cthulhu-audio down")
  , ("<XF86AudioMute>",        spawn "$HOME/.local/bin/cthulhu-audio mute")
  , ("<XF86AudioMicMute>",     spawn "$HOME/.local/bin/cthulhu-audio mic")

  , ("M-C-r", spawn "xmonad --recompile && xmonad --restart")
  ]

Config
  { font = "xft:Hack:size=11"
  , bgColor = "#181616"
  , fgColor = "#c5c9c5"
  , position = OnScreen 0 (TopSize C 100 28)
  , lowerOnStart = False
  , hideOnStart = False
  , overrideRedirect = True
  , allDesktops = True
  , persistent = True
  , sepChar = "%"
  , alignSep = "}{"
  , template = " }<action=`gsimplecal` button=1><fc=#c4b28a>%date%</fc></action>{  <action=`pavucontrol` button=3><fc=#87a987>VOL</fc> %volume%</action>   "
  , commands =
      [ Run Date "%H:%M" "date" 100
      , Run Com "sh" ["-c", "\"$HOME/.local/bin/cthulhu-audio\" status"] "volume" 10
      ]
  }

# Transparenz

# Schriftgröße (falls du sie anpassen willst)
font_size 11.0

# Scrollback-Puffer (wie weit du hochscrollen kannst)
scrollback_lines 10000

# Klickbare Links aktivieren
detect_urls yes

background_opacity 0.8


# BEGIN_KITTY_THEME
# Kanagawa_dragon
include current-theme.conf
# END_KITTY_THEME

# vim:ft=kitty

## name: Kanagawa_dragon
## license: MIT
## author: Tommaso Laurenzi
## upstream: https://github.com/rebelot/kanagawa.nvim/
## blurb: NeoVim dark colorscheme inspired by the colors of the famous painting
## by Katsushika Hokusai. Dragon version.

#: The basic colors

foreground                      #c5c9c5
background                      #181616
selection_foreground            #c8c093
selection_background            #2d4f67

#: Cursor colors

cursor                          #c8c093

#: URL underline color when overing with mouse

url_color                       #72a7bc

#: Tab bar colors

active_tab_foreground           #c8c093
active_tab_background           #12120f
inactive_tab_foreground         #a6a69c
inactive_tab_background         #12120f

#: The basic 16 colors

#: black
color0  #0d0c0c
color8  #a6a69c

#: red
color1  #c4746e
color9  #e46876

#: green
color2  #8a9a7b
color10 #87a987

#: yellow
color3  #c4b28a
color11 #e6c384

#: blue
color4  #8ba4b0
color12 #7fb4ca

#: magenta
color5  #a292a3
color13 #938aa9

#: cyan
color6  #8ea4a2
color14 #7aa89f

#: white
color7  #c8c093
color15 #c5c9c5


#: You can set the remaining 240 colors as color16 to color255.

color16 #b6927b
color17 #b98d7b

[global]
    monitor = 0
    follow = none
    origin = top-right
    offset = (16, 44)
    width = 320
    height = (0, 180)
    notification_limit = 3

    font = Hack 10
    corner_radius = 10
    frame_width = 2
    separator_height = 4
    padding = 12
    horizontal_padding = 14
    gap_size = 6

    transparency = 5
    progress_bar = true
    progress_bar_height = 7
    progress_bar_frame_width = 0
    progress_bar_corner_radius = 3
    highlight = "#87a987"

[urgency_low]
    background = "#181616"
    foreground = "#c5c9c5"
    frame_color = "#737c73"
    timeout = 3

[urgency_normal]
    background = "#181616"
    foreground = "#c5c9c5"
    frame_color = "#87a987"
    timeout = 4

[urgency_critical]
    background = "#181616"
    foreground = "#c4746e"
    frame_color = "#c4746e"
    timeout = 0

configuration {
    modi: "drun,run";
    show-icons: true;
    font: "Hack 11";
    drun-display-format: "{name}";
}

* {
    bg: #181616;
    bg-alt: #282727;
    fg: #c5c9c5;
    green: #87a987;
    muted: #737c73;
    selected: #393836;
}

window {
    width: 650px;
    location: center;
    anchor: center;
    background-color: @bg;
    border: 2px;
    border-color: @green;
    border-radius: 12px;
    padding: 16px;
}

mainbox {
    spacing: 12px;
    children: [ inputbar, listview ];
}

inputbar {
    background-color: @bg-alt;
    border-radius: 8px;
    padding: 12px;
    spacing: 10px;
    children: [ prompt, entry ];
}

prompt {
    text-color: @green;
}

entry {
    text-color: @fg;
    placeholder: "Anwendung suchen...";
    placeholder-color: @muted;
}

listview {
    lines: 8;
    columns: 1;
    spacing: 5px;
    scrollbar: false;
}

element {
    padding: 9px;
    spacing: 12px;
    border-radius: 7px;
}

element normal.active {
    background-color: @bg;
    text-color: @green;
}

element selected.normal {
    background-color: @selected;
    text-color: @green;
}

element-icon {
    size: 22px;
}

element-text {
    text-color: @fg;
}

#!/usr/bin/env bash
set -euo pipefail
export LC_ALL=C

case "${1:-}" in
  up)   wpctl set-volume -l 1.0 @DEFAULT_AUDIO_SINK@ 5%+ ;;
  down) wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%- ;;
  mute) wpctl set-mute @DEFAULT_AUDIO_SINK@ toggle ;;
  mic)  wpctl set-mute @DEFAULT_AUDIO_SOURCE@ toggle ;;
  status) ;; # Read-only mode used by Xmobar; no notification.
  *) printf 'Usage: cthulhu-audio {up|down|mute|mic|status}\n' >&2; exit 2 ;;
esac

if [[ "$1" == mic ]]; then
  state="$(wpctl get-volume @DEFAULT_AUDIO_SOURCE@)"
  if [[ "$state" == *"[MUTED]"* ]]; then
    dunstify -a Cthulhu -r 41002 -t 1800 "Mikrofon" "Stummgeschaltet"
  else
    dunstify -a Cthulhu -r 41002 -t 1800 "Mikrofon" "Aktiv"
  fi
else
  state="$(wpctl get-volume @DEFAULT_AUDIO_SINK@)"
  percent="$(awk '{printf "%.0f", $2 * 100}' <<< "$state")"
  if [[ "$1" == status ]]; then
    if [[ "$state" == *"[MUTED]"* ]]; then printf 'MUTE\n'; else printf '%s%%\n' "$percent"; fi
  elif [[ "$state" == *"[MUTED]"* ]]; then
    dunstify -a Cthulhu -r 41001 -t 1800 -h int:value:0 "Audio" "Stummgeschaltet"
  else
    dunstify -a Cthulhu -r 41001 -t 1800 -h "int:value:$percent" "Lautstärke" "$percent%"
  fi
fi

[Settings]
gtk-theme-name=Kanagawa-Green-Dark-Dragon
gtk-application-prefer-dark-theme=true
gtk-button-images=true
gtk-cursor-blink=true
gtk-cursor-blink-time=1000
gtk-cursor-theme-name=Bibata-Modern-Classic
gtk-cursor-theme-size=24
gtk-decoration-layout=icon:minimize,maximize,close
gtk-enable-animations=true
gtk-font-name=Noto Sans,  10
gtk-icon-theme-name=breeze-dark
gtk-menu-images=true
gtk-primary-button-warps-slider=true
gtk-sound-theme-name=ocean
gtk-toolbar-style=3
gtk-xft-dpi=98304

[Settings]
gtk-application-prefer-dark-theme=true
gtk-cursor-blink=true
gtk-cursor-blink-time=1000
gtk-cursor-theme-name=Bibata-Modern-Classic
gtk-cursor-theme-size=24
gtk-decoration-layout=icon:minimize,maximize,close
gtk-enable-animations=true
gtk-font-name=Noto Sans,  10
gtk-icon-theme-name=breeze-dark
gtk-primary-button-warps-slider=true
gtk-sound-theme-name=ocean
gtk-xft-dpi=98304

{
  "$schema": "https://github.com/fastfetch-cli/fastfetch/raw/dev/doc/json_schema.json",
  "logo": "~/.config/fastfetch/1.png",
  "logoType": "kitty-icat",
  "logoWidth": 30,
  "logoHeight": 15,
  "logoPadding": {
    "top": 1,
    "left": 2,
    "right": 4
  },
  "display": {
    "separator": " "
  },
  "modules": [
    {
      "key": "╭───────────╮",
      "type": "custom"
    },
    {
      "key": "│  user    │",
      "type": "title",
      "format": "{user-name}"
    },
    {
      "key": "│ 󰇅 hname   │",
      "type": "title",
      "format": "{host-name}"
    },
    {
      "key": "│ 󰅐 uptime  │",
      "type": "uptime"
    },
    {
      "key": "│  distro  │",
      "type": "os",
      "format": "I use NixOS btw"
    },
    {
      "key": "│  kernel  │",
      "type": "kernel"
    },
    {
      "key": "│  wm      │",
      "type": "wm"
    },
    {
      "key": "│  term    │",
      "type": "terminal"
    },
    {
      "key": "│  shell   │",
      "type": "shell"
    },
    {
      "key": "│ 󰍛 cpu     │",
      "type": "cpu",
      "showPeCoreCount": true
    },
    {
      "key": "│ 󰉉 root    │",
      "type": "disk",
      "folders": "/"
    },
    {
      "key": "│  memory  │",
      "type": "memory"
    },
    {
      "key": "│ 󰓡 swap    │",
      "type": "swap"
    },
    {
      "key": "├───────────┤",
      "type": "custom"
    },
    {
      "key": "│ PC        │",
      "type": "host",
      "format": "{5} {1} ({2})"
    },
    {
      "key": "│ ├ 󰢮 gpu   │",
      "type": "gpu",
      "format": "{1} {2} @ {12}"
    },
    {
      "key": "│ ├  disp  │",
      "type": "display",
      "order": "desc",
      "format": "{1}x{2} @ {3} Hz"
    },
    {
      "key": "│ └  age   │",
      "type": "command",
      "text": "marker=\"$HOME/.config/fastfetch/cthulhu-born\"; if [ -f \"$marker\" ]; then birth_install=$(stat -c %Y \"$marker\"); current=$(date +%s); echo $(((current - birth_install) / 86400)) days; else printf \"marker missing\\n\"; fi"
    },
    {
      "key": "│  colors  │",
      "type": "colors",
      "symbol": "circle"
    },
    {
      "key": "╰───────────╯",
      "type": "custom"
    }
  ]
}

{
    "workbench.colorTheme": "Kanagawa Dragon",
    "workbench.iconTheme": "material-icon-theme",
    "editor.fontFamily": "'Hack', monospace"
}

#!/usr/bin/env bash
set -euo pipefail

# Run xrandr, adapt outputs/modes, then opt in. False preserves your layout.
configure_layout=false
primary=DP-2
secondary=HDMI-1
if "$configure_layout"; then
  if ! xrandr --output "$primary" --primary --mode 3440x1440 --rate 144 --pos 0x0 \
      --output "$secondary" --mode 1920x1080 --rate 60 --pos 3440x0; then
    printf 'Monitor layout failed; check xrandr output and supported modes.\n' >&2
  fi
fi

# Supply your own artwork. feh's Xinerama monitor order decides assignment.
wallpaper_dir="${1:-$HOME/Bilder/wallpaper}"
images=()
for image in "$wallpaper_dir/1.png" "$wallpaper_dir/2.png"; do
  [[ ! -f "$image" ]] || images+=("$image")
done
if ((${#images[@]})); then
  feh --bg-max "${images[@]}"
else
  xsetroot -solid '#181616'
fi

#!/usr/bin/env bash
# Installs home/ only. No sudo, package management or display-manager changes.
set -euo pipefail
source_root="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
target="${1:-$HOME}"
[[ $# -le 1 && "$target" = /* && "$target" != / && -d "$target" ]] || {
  printf 'Usage: bash install-user.sh [existing-absolute-home-directory]\n' >&2; exit 2;
}
target="$(realpath -- "$target")"
[[ "$target" != / ]] || { printf 'Refusing filesystem root.\n' >&2; exit 2; }
[[ ! -d "$target/.config/xmonad" ]] || {
  printf 'Existing .config/xmonad takes precedence. Review it before installing .xmonad.\n' >&2; exit 1;
}
mapfile -d '' files < <(find "$source_root/home" -type f -print0 | sort -z)
# Check all conflicts before creating files. Never traverse destination symlinks.
for file in "${files[@]}"; do
  relative="${file#"$source_root/home/"}"
  destination="$target/$relative"
  parent="$destination"
  while [[ "$parent" != "$target" ]]; do
    [[ ! -L "$parent" ]] || { printf 'Refusing symlink: %s\n' "$parent" >&2; exit 1; }
    parent="$(dirname -- "$parent")"
    [[ ! -e "$parent" || -d "$parent" ]] || {
      printf 'Not a directory: %s\n' "$parent" >&2; exit 1;
    }
  done
  if [[ -e "$destination" ]] && ! cmp -s -- "$file" "$destination"; then
    printf 'Conflict: %s\nBack it up and move it aside, then rerun. No files installed.\n' "$destination" >&2
    exit 1
  fi
done
for file in "${files[@]}"; do
  destination="$target/${file#"$source_root/home/"}"
  mkdir -p -- "$(dirname -- "$destination")"
  if [[ ! -e "$destination" ]]; then
    (set -o noclobber; cat -- "$file" > "$destination")
    printf 'Installed %s\n' "$destination"
  fi
done
chmod +x -- "$target/.local/bin/cthulhu-audio" "$target/.config/cthulhu/monitors.sh"
marker="$target/.config/fastfetch/cthulhu-born"
if [[ ! -e "$marker" && ! -L "$marker" ]]; then
  (set -o noclobber; : > "$marker")
fi
printf 'Done. Add your own artwork; edit monitors.sh and review the installation guide.\n'

sudo nixos-rebuild switch --rollback