Harden HF runtime: no-op segmentation, safe dropdown, disable hot reload

app.py

@@ -7,6 +7,8 @@ from app.ui import build_ui
 
 
 def main() -> None:
+    # Spaces hot reload requires newer client; disable to avoid runtime crashes.
+    os.environ.setdefault("GRADIO_HOT_RELOAD", "0")
     demo = build_ui()
     use_queue = os.getenv("DA_USE_QUEUE")
     use_queue_flag = False if use_queue is None else use_queue.lower() not in {"0", "false", "no"}

app/segmentation.py

@@ -144,10 +144,15 @@ class SegmenterService:
             self._segmenters[model_id] = SemanticSegmenter(model_id)
         except Exception as exc:
             print(f"[WARN] Failed to preload segmentation model {model_id}: {exc}")
+            self._segmenters[model_id] = _NoOpSegmenter()
 
     def _get_segmenter(self, model_id: str) -> SemanticSegmenter:
         if model_id not in self._segmenters:
-            self._segmenters[model_id] = SemanticSegmenter(model_id)
+            try:
+                self._segmenters[model_id] = SemanticSegmenter(model_id)
+            except Exception as exc:
+                print(f"[WARN] Segmentation unavailable for {model_id}; using no-op segmenter: {exc}")
+                self._segmenters[model_id] = _NoOpSegmenter()
         return self._segmenters[model_id]
 
     def get_masks(self, request: SegmenterRequest, model_id: str | None = None) -> dict[str, np.ndarray]:
@@ -186,6 +191,13 @@ class SegmenterService:
         return result
 
 
+class _NoOpSegmenter:
+    """Fallback segmenter when the real model cannot be loaded (e.g., gated repo)."""
+
+    def segment(self, image, max_side, prompts, score_threshold, mask_threshold):
+        return {}
+
+
 __all__ = ["SegmenterService", "SegmenterRequest", "SemanticSegmenter"]
 
 # Shared singleton to avoid reloads across analyzer instances

app/ui.py

@@ -146,7 +146,8 @@ def build_ui(analyzer: SafetyAnalyzer | None = None) -> gr.Blocks:
                 input_path = gr.Dropdown(
                     label="Input file",
                     choices=data_inputs,
-                    value=data_inputs[0] if data_inputs else "",
+                    value=data_inputs[0] if data_inputs else None,
+                    allow_custom_value=True,
                     info="Pick any VISLOC image under data/Image/VISLOC/.",
                 )
                 model_id = defaults.model_id