From 0d14c3cc5b94aceef28f1991ae7ef2f973e43bd2 Mon Sep 17 00:00:00 2001
From: Arnout Engelen <arnout@bzzt.net>
Date: Tue, 20 May 2025 22:16:12 +0200
Subject: [PATCH] nixos: autoUpgrade: allow disabling flake upgrades

When auto-upgrading based on a flake, it might be desirable to
only upgrade to the newer flake, without updating the nixpkgs
from the flake lock. This option makes that possible.
---
 nixos/modules/tasks/auto-upgrade.nix | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/tasks/auto-upgrade.nix b/nixos/modules/tasks/auto-upgrade.nix
index 0d3756a772f4..4effda9ef4cd 100644
--- a/nixos/modules/tasks/auto-upgrade.nix
+++ b/nixos/modules/tasks/auto-upgrade.nix
@@ -61,6 +61,16 @@ in
         '';
       };
 
+      upgrade = lib.mkOption {
+        type = lib.types.bool;
+        default = true;
+        description = ''
+          Disable adding the `--upgrade` parameter when `channel`
+          is not set, such as when upgrading to the latest version
+          of a flake honouring its lockfile.
+        '';
+      };
+
       flags = lib.mkOption {
         type = lib.types.listOf lib.types.str;
         default = [ ];
@@ -235,7 +245,7 @@ in
           date = "${pkgs.coreutils}/bin/date";
           readlink = "${pkgs.coreutils}/bin/readlink";
           shutdown = "${config.systemd.package}/bin/shutdown";
-          upgradeFlag = lib.optional (cfg.channel == null) "--upgrade";
+          upgradeFlag = lib.optional (cfg.channel == null && cfg.upgrade) "--upgrade";
         in
         if cfg.allowReboot then
           ''