Fix ZeroGPU by manually triggering startup_report during FastAPI startup

app.py

@@ -892,6 +892,28 @@ app = gr.mount_gradio_app(
 async def startup_event():
     logger.info("Starting up FastAPI application...")
     await _ensure_init()
+    
+    # --- Hugging Face ZeroGPU Fix ---
+    # When using gr.mount_gradio_app with a custom FastAPI app, gr.Blocks.launch()
+    # is bypassed. The `spaces` library hooks `.launch()` to emit the `startup_report`
+    # required by ZeroGPU orchestrator to verify `@spaces.GPU` functions exist. 
+    # Without this report, the Hub errors out with "No @spaces.GPU function detected".
+    # Therefore, we manually trigger it here.
+    try:
+        from spaces import config
+        if getattr(config.Config, "zero_gpu", False):
+            import spaces.zero as zero
+            if hasattr(zero, "startup"):
+                zero.startup()
+                logger.info("Triggered ZeroGPU startup successfully.")
+            elif hasattr(zero, "client"):
+                zero.torch.pack()
+                zero.client.startup_report()
+                logger.info("Triggered ZeroGPU client startup manually.")
+    except ImportError:
+        pass
+    except Exception as e:
+        logger.warning(f"Failed to manually trigger ZeroGPU startup report: {e}")
 
 if __name__ == "__main__":
     import uvicorn