From 9b38a54d16424086b3d87ea09b45fcd7f0c1fbdb Mon Sep 17 00:00:00 2001
From: Christine Elisabeth Koppel <kuutruu@posteo.net>
Date: Thu, 12 Feb 2026 19:22:17 +0100
Subject: [PATCH] Create a dummy file system.

---
 nix-system-configs/modules/system/build_machine.nix | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/nix-system-configs/modules/system/build_machine.nix b/nix-system-configs/modules/system/build_machine.nix
index b7828e4..f3e754d 100644
--- a/nix-system-configs/modules/system/build_machine.nix
+++ b/nix-system-configs/modules/system/build_machine.nix
@@ -5,6 +5,15 @@
   ...
 }: let
   choose = paths: builtins.head (builtins.filter (p: builtins.pathExists p) paths);
+
+  # Dummy filesystem config for dry-run evaluation
+  dummyFileSystems = {
+    fileSystems."/" = {
+      device = "/dev/disk/by-label/nixos";
+      fsType = "ext4";
+    };
+  };
+
 in {
   options.local = {
     hostname = lib.mkOption {
@@ -35,7 +44,8 @@ in {
     (choose [ ./modules/lix-default.nix ../lix-default.nix ])
     (choose [ ./modules/secrets-config/sops-build-machine.nix ../secrets-config/sops-build-machine.nix ])
     ## TODO: Make this more elegant and less risky for unexpected errors happening.
-  ] ++ lib.optional (builtins.pathExists ./hardware-configuration.nix) ./hardware-configuration.nix;
+  ] ++ lib.optional (builtins.pathExists ./hardware-configuration.nix) ./hardware-configuration.nix
+      ++ lib.optional (!builtins.pathExists ./hardware-configuration.nix) dummyFileSystems;
 
   config = {
     # Local metadata