nixos/znapzend: fix when no previous zetup

When the znapzend module was enabled for the first time with pure =
true; then the list of previous entries is empty, but xargs still tried
to execute a znapzendzetup delete command with no arguments, which made
it fail

1 files changed, 1 insertions, 1 deletions

diff --git a/nixos/modules/services/backup/znapzend.nix b/nixos/modules/services/backup/znapzend.nix
index 762bb4b38675..3d133f82d204 100644
--- a/nixos/modules/services/backup/znapzend.nix
+++ b/nixos/modules/services/backup/znapzend.nix
@@ -386,7 +386,7 @@ in
           echo Resetting znapzend zetups
           ${pkgs.znapzend}/bin/znapzendzetup list \
             | grep -oP '(?<=\*\*\* backup plan: ).*(?= \*\*\*)' \
-            | xargs ${pkgs.znapzend}/bin/znapzendzetup delete
+            | xargs -I{} ${pkgs.znapzend}/bin/znapzendzetup delete "{}"
         '' + concatStringsSep "\n" (mapAttrsToList (dataset: config: ''
           echo Importing znapzend zetup ${config} for dataset ${dataset}
           ${pkgs.znapzend}/bin/znapzendzetup import --write ${dataset} ${config}