updated PYTHONPATH to "${self}/"

common/global/default.nix

@@ -44,7 +44,10 @@
     # firmware update
     fwupd.enable = true;
 
-    snapshot_manager.enable = lib.mkDefault true;
+    snapshot_manager = {
+      enable = lib.mkDefault true;
+      PYTHONPATH = "${inputs.self}/";
+    };
 
     zfs = {
       trim.enable = lib.mkDefault true;

common/global/snapshot_manager.nix

@@ -16,6 +16,12 @@ in
         default = ./snapshot_config.toml;
         description = "Path to the snapshot_manager TOML config.";
       };
+      PYTHONPATH = lib.mkOption {
+        type = lib.types.str;
+        description = ''
+          the PYTHONPATH to use for the snapshot_manager service.
+        '';
+      };
       EnvironmentFile = lib.mkOption {
         type = lib.types.nullOr (lib.types.coercedTo lib.types.path toString lib.types.str);
         default = null;
@@ -35,7 +41,7 @@ in
         after = [ "zfs-import.target" ];
         path = [ pkgs.zfs ];
         environment = {
-          PYTHONPATH = "${../..}/";
+          PYTHONPATH = cfg.PYTHONPATH;
         };
         serviceConfig = {
           Type = "oneshot";