diff --git a/tools/network_timing_benchmark.py b/tools/network_timing_benchmark.py
index 9f26f11..f1c5488 100755
--- a/tools/network_timing_benchmark.py
+++ b/tools/network_timing_benchmark.py
@@ -831,13 +831,22 @@ def run_flent(args: argparse.Namespace, out_dir: Path) -> list[dict[str, Any]]:
             iface=args.interface,
             timeout=args.flent_duration + args.command_timeout_extra + 60,
         )
+        error = result.stderr.strip() if result.returncode not in (0, None) else None
+        if error and "No module named 'distutils'" in error:
+            error += (
+                "\nHint: Flent is running with a Python environment that cannot import distutils. "
+                "On Ubuntu, install python3-setuptools or run Flent from a virtual environment "
+                "with setuptools installed."
+            )
+        data_file_exists = data_file.is_file()
         results.append(
             {
                 "type": "flent",
                 "test": test_name,
                 "data_file": str(data_file),
+                "data_file_exists": data_file_exists,
                 "meta": meta,
-                "error": result.stderr.strip() if result.returncode not in (0, None) else None,
+                "error": error,
             }
         )
     return results
@@ -1039,7 +1048,12 @@ def write_summary_md(summary: dict[str, Any], out_dir: Path) -> None:
         elif result_type == "sockperf":
             lines.append(f"- `sockperf` `{result.get('protocol')}`: {result.get('extracted')}")
         elif result_type == "flent":
-            lines.append(f"- `flent` `{result.get('test')}`: data={result.get('data_file')}")
+            exists_text = "created" if result.get("data_file_exists") else "missing"
+            lines.append(
+                f"- `flent` `{result.get('test')}`: data={result.get('data_file')} ({exists_text})"
+            )
+            if result.get("error"):
+                lines.append(f"- `flent` `{result.get('test')}` error: `{result.get('error')}`")
         else:
             lines.append(f"- `{result_type}`: raw={result.get('meta', {}).get('raw_output')}")