From 06103d4258a54b5d0d36759ff1e8c3e0daf8f0ad Mon Sep 17 00:00:00 2001
From: David Heinemeier Hansson <david@hey.com>
Date: Mon, 11 Aug 2025 17:00:19 +0200
Subject: [PATCH] Omarchy is exclusively for vanilla Arch without Gnome or KDE
 installed (#524)

---
 install.sh                 |  1 +
 install/preflight/guard.rb | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 install/preflight/guard.rb

diff --git a/install.sh b/install.sh
index 2f2bd489..a0240dd4 100755
--- a/install.sh
+++ b/install.sh
@@ -27,6 +27,7 @@ show_subtext() {
 }
 
 # Install prerequisites
+source $OMARCHY_INSTALL/preflight/guard.sh
 source $OMARCHY_INSTALL/preflight/aur.sh
 source $OMARCHY_INSTALL/preflight/presentation.sh
 source $OMARCHY_INSTALL/preflight/migrations.sh
diff --git a/install/preflight/guard.rb b/install/preflight/guard.rb
new file mode 100644
index 00000000..dad66834
--- /dev/null
+++ b/install/preflight/guard.rb
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+abort() {
+  echo -e "\e[31mOmarchy is only designed for a fresh Arch install!\e[0m"
+  exit 1
+}
+
+# Must be an Arch distro
+[[ -f /etc/arch-release ]] || abort
+
+# Must not be an Arch derivative distro
+for marker in /etc/cachyos-release /etc/eos-release /etc/garuda-release /etc/manjaro-release; do
+  [[ -f "$marker" ]] && abort
+done
+
+# Must not have Gnome or KDE already install
+pacman -Qe gnome-shell &>/dev/null && abort
+pacman -Qe plasma-desktop &>/dev/null && abort