Update app.py

app.py

@@ -228,6 +228,9 @@ def generate(
     steps: int = 4,
     secret_token: str = "",
 ) -> Image.Image:
+    # Declare global BEFORE any reference or assignment to GPU_COLD
+    global GPU_COLD
+
     if secret_token != SECRET_TOKEN:
         raise gr.Error("Invalid secret token. Set SECRET_TOKEN or pass the correct token.")
 
@@ -260,7 +263,6 @@ def generate(
         _p.to("cpu", torch.float32)
 
     # mark that we've done our cold GPU upload for this process
-    global GPU_COLD
     if moved_to_cuda:
         GPU_COLD = False