From dda895b551c7cf56476ac8892904e289a4d8b920 Mon Sep 17 00:00:00 2001
From: ibizaman <ibizaman@tiserbox.com>
Date: Sat, 1 Nov 2025 13:49:20 +0100
Subject: [PATCH] nixos/borgbackup: add option to override state directory

---
 nixos/modules/services/backup/borgbackup.nix | 23 +++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/nixos/modules/services/backup/borgbackup.nix b/nixos/modules/services/backup/borgbackup.nix
index adabb2ce0f8b..82baeb928398 100644
--- a/nixos/modules/services/backup/borgbackup.nix
+++ b/nixos/modules/services/backup/borgbackup.nix
@@ -136,7 +136,7 @@ let
   mkBackupService =
     name: cfg:
     let
-      userHome = config.users.users.${cfg.user}.home;
+      userHome = if cfg.stateDir != null then cfg.stateDir else config.users.users.${cfg.user}.home;
       backupJobName = "borgbackup-job-${name}";
       backupScript = mkBackupScript backupJobName cfg;
     in
@@ -177,6 +177,7 @@ let
       environment = {
         BORG_REPO = cfg.repo;
       }
+      // (lib.optionalAttrs (cfg.stateDir != null) { BORG_BASE_DIR = cfg.stateDir; })
       // (mkPassEnv cfg)
       // cfg.environment;
     };
@@ -223,6 +224,7 @@ let
       set = {
         BORG_REPO = cfg.repo;
       }
+      // (lib.optionalAttrs (cfg.stateDir != null) { BORG_BASE_DIR = cfg.stateDir; })
       // (mkPassEnv cfg)
       // cfg.environment;
     });
@@ -232,14 +234,15 @@ let
     name: cfg:
     let
       settings = { inherit (cfg) user group; };
+      userHome = if cfg.stateDir != null then cfg.stateDir else config.users.users.${cfg.user}.home;
     in
     lib.nameValuePair "borgbackup-job-${name}" (
       {
         # Create parent dirs separately, to ensure correct ownership.
-        "${config.users.users."${cfg.user}".home}/.config".d = settings;
-        "${config.users.users."${cfg.user}".home}/.cache".d = settings;
-        "${config.users.users."${cfg.user}".home}/.config/borg".d = settings;
-        "${config.users.users."${cfg.user}".home}/.cache/borg".d = settings;
+        "${userHome}/.config".d = settings;
+        "${userHome}/.cache".d = settings;
+        "${userHome}/.config/borg".d = settings;
+        "${userHome}/.cache/borg".d = settings;
       }
       // lib.optionalAttrs (isLocalPath cfg.repo && !cfg.removableDevice) {
         "${cfg.repo}".d = settings;
@@ -487,6 +490,16 @@ in
               default = "root";
             };
 
+            stateDir = lib.mkOption {
+              type = lib.types.nullOr lib.types.str;
+              description = ''
+                Override the directory in which {command}`borg` stores its
+                configuration and cache. By default it uses the user's
+                home directory but is some cases this can cause conflicts.
+              '';
+              default = null;
+            };
+
             wrapper = lib.mkOption {
               type = with lib.types; nullOr str;
               description = ''
-- 
2.50.1