diff --git a/aztk/spark/client/cluster/helpers/diagnostics.py b/aztk/spark/client/cluster/helpers/diagnostics.py
index fbd6ef70..e99f432f 100644
--- a/aztk/spark/client/cluster/helpers/diagnostics.py
+++ b/aztk/spark/client/cluster/helpers/diagnostics.py
@@ -13,17 +13,18 @@ def _run(spark_cluster_operations, cluster_id, output_directory=None):
     ssh_cmd = _build_diagnostic_ssh_command()
     run_output = spark_cluster_operations.run(cluster_id, ssh_cmd, host=True)
     remote_path = "/tmp/debug.zip"
+    result = None
     if output_directory:
         local_path = os.path.join(os.path.abspath(output_directory), "debug.zip")
-        output = spark_cluster_operations.download(cluster_id, remote_path, local_path, host=True)
+        result = spark_cluster_operations.download(cluster_id, remote_path, local_path, host=True)
 
         # write run output to debug/ directory
         with open(os.path.join(os.path.dirname(local_path), "debug-output.txt"), 'w', encoding="UTF-8") as f:
             [f.write(line + '\n') for node_output in run_output for line in node_output.output]
     else:
-        output = spark_cluster_operations.download(cluster_id, remote_path, host=True)
+        result = spark_cluster_operations.download(cluster_id, remote_path, host=True)
 
-    return output
+    return result
 
 
 def _build_diagnostic_ssh_command():