From 080cd5b1cc5f267e27715e2622f542d8425b89bc Mon Sep 17 00:00:00 2001
From: Artem Sheremet <dot.doom@gmail.com>
Date: Fri, 15 May 2026 19:55:18 +0000
Subject: [PATCH] Fix undefined variable when deployed in NixOS

---
 modules/home/common.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/modules/home/common.nix b/modules/home/common.nix
index 562f6b2..925c7f4 100644
--- a/modules/home/common.nix
+++ b/modules/home/common.nix
@@ -21,7 +21,10 @@
   '';
 
   home.activation.report-changes = lib.hm.dag.entryAnywhere ''
-    ${pkgs.nvd}/bin/nvd diff $oldGenPath $newGenPath
+    # oldGenPath can be undefined with home-manager used as part of NixOS config
+    if [ -n "''${oldGenPath+x}" ]; then
+      ${pkgs.nvd}/bin/nvd diff $oldGenPath $newGenPath
+    fi
   '';
 
   programs.git = {