added debugging message for inference

app.py

@@ -622,8 +622,17 @@ def run_pi0_inference(request: InferenceRequest) -> Tuple[Optional[str], str]:
         # Send request
         request_dict = request.to_dict()
         request_json = json.dumps(request_dict)
-        worker.stdin.write(request_json + "\n")
-        worker.stdin.flush()
+        print(f"DEBUG: Sending request to {model_key} worker: {request_json[:150]}...", flush=True)
+        try:
+            worker.stdin.write(request_json + "\n")
+            worker.stdin.flush()
+        except BrokenPipeError:
+            # Worker died - restart it
+            print(f"⚠️  Worker {model_key} stdin broken, restarting...", flush=True)
+            _INFERENCE_WORKERS[model_key] = None
+            worker = get_inference_worker(model_key)
+            worker.stdin.write(request_json + "\n")
+            worker.stdin.flush()
         
         request.progress(0.2, desc="Waiting for inference result...")
         

inference_openpi.py

@@ -535,8 +535,12 @@ def main():
                 continue
             
             try:
+                print(f"DEBUG: Starting inference for task: {request.get('task_name', 'unknown')}", file=sys.stderr, flush=True)
                 result = run_inference(request)
-                print(json.dumps(result), flush=True)
+                print(f"DEBUG: Inference completed, sending result", file=sys.stderr, flush=True)
+                result_json = json.dumps(result)
+                print(result_json, flush=True)
+                print(f"DEBUG: Result sent successfully", file=sys.stderr, flush=True)
             except Exception as e:
                 # Error during inference - send error response as JSON
                 import traceback
@@ -548,7 +552,9 @@ def main():
                     "status_message": f"❌ Worker error: {str(e)}",
                     "error": str(e)
                 }
-                print(json.dumps(error_result), flush=True)
+                error_json = json.dumps(error_result)
+                print(error_json, flush=True)
+                print(f"DEBUG: Error result sent successfully", file=sys.stderr, flush=True)
             
         except KeyboardInterrupt:
             print("===== OpenPI Worker: interrupted =====", file=sys.stderr, flush=True)