all: toggle system update based off status of the tree

Dirty means we are doing development on something so don't autoUpgrade
the changes away.

flake.nix

@@ -76,7 +76,15 @@
         flakes.taskobs.overlay
       ];
 
-      buildVer = { system.configurationRevision = self.rev or "DIRTY"; };
+      # Set our configurationRevison based on the status of our git repo.
+      # If the repo is dirty, disable autoUpgrade as it means we are
+      # testing something.
+      buildVer = let state = self.rev or "DIRTY";
+      in {
+        system.configurationRevision = state;
+        system.autoUpgrade.enable = (state != "DIRTY");
+      };
+
       buildShell = pkgs:
         pkgs.mkShell {
           shellHook = ''

system/update.nix

@@ -14,7 +14,8 @@ with lib; {
   config = mkMerge [
     (mkIf config.autoUpdate.enable {
       system.autoUpgrade = {
-        enable = true;
+        # enable is set in flake depending on the state of the tree
+        # DIRTY means disabled, git revision means enabled
         allowReboot = mkDefault false;
         flake = "github:qbit/xin";
         dates = "*-*-* *:05:00";