small refactor

zfs_backup.py

@@ -99,7 +99,7 @@ class Manager:
     def _send_incremental(
         self, local_dataset: Dataset, remote_dataset: Dataset
     ) -> Popen | None:
-        """Send incremental stream between two datasets to remote."""
+        """Send incremental stream between two datasets to remote, return the pipe. If local and remote snapshot are identical, perform nothing and return None."""
         start_snapshot = self._get_newest_common_snapshot_with_backup_tags(
             local_dataset, remote_dataset
         )
@@ -118,8 +118,7 @@ class Manager:
         """From all snapshots in the dataset, get the newest one that matches the backup tags in the config."""
         snapshots = self._find_snapshots_with_backup_tag(dataset)
         snapshots.sort()
-        end_snapshot = snapshots[-1]
-        return end_snapshot
+        return snapshots[-1]
 
     @property
     def _datasets_to_backup(self) -> list[Dataset]:
@@ -848,4 +847,8 @@ def _verify_running_as_root() -> None:
 
 
 if __name__ == "__main__":
-    main()
+    try:
+        main()
+    except Exception as e:
+        print(e)
+        exit(EXIT_ERROR)