Fix output

src/cli/output.rs

@@ -29,8 +29,11 @@ fn write_csv_positions<R: Rng, P: Position, S: Storage<P>, W: Walker<P>, Sp: Spa
         .map(|line| &line.position)
         .collect();
 
-    wtr.serialize(positions)
-        .unwrap();
+    positions
+        .iter()
+        .for_each(|position|
+            wtr.serialize(position).expect("Failed to write row")
+        );
 
     wtr.flush()
         .unwrap();