fix(folder-paths): include searched model directories in errors

folder_paths.py

@@ -370,9 +370,19 @@ def get_full_path_or_raise(folder_name: str, filename: str) -> str:
     """
     Get the full path of a file in a folder, has to be a file
     """
-    full_path = get_full_path(folder_name, filename)
+    canonical_folder_name = map_legacy(folder_name)
+    full_path = get_full_path(canonical_folder_name, filename)
     if full_path is None:
-        raise FileNotFoundError(f"Model in folder '{folder_name}' with filename '{filename}' not found.")
+        search_paths = folder_names_and_paths.get(canonical_folder_name, ([], set()))[0]
+        mapped_note = f" (mapped to '{canonical_folder_name}')" if canonical_folder_name != folder_name else ""
+        if search_paths:
+            raise FileNotFoundError(
+                f"Model in folder '{folder_name}'{mapped_note} with filename '{filename}' not found. "
+                f"Searched in: {', '.join(search_paths)}"
+            )
+        raise FileNotFoundError(
+            f"Model in folder '{folder_name}'{mapped_note} with filename '{filename}' not found and no search paths are registered."
+        )
     return full_path
 
 

tests-unit/comfy_test/folder_path_test.py

@@ -160,3 +160,30 @@ def test_base_path_change_clears_old(set_base_dir):
 
     for name in ["controlnet", "diffusion_models", "text_encoders"]:
         assert len(folder_paths.get_folder_paths(name)) == 2
+
+
+def test_get_full_path_or_raise_includes_search_paths(clear_folder_paths, temp_dir):
+    first_dir = os.path.join(temp_dir, "first")
+    second_dir = os.path.join(temp_dir, "second")
+    folder_paths.add_model_folder_path("test_folder", first_dir, is_default=True)
+    folder_paths.add_model_folder_path("test_folder", second_dir, is_default=False)
+
+    with pytest.raises(FileNotFoundError) as exc_info:
+        folder_paths.get_full_path_or_raise("test_folder", "missing_model.safetensors")
+
+    message = str(exc_info.value)
+    assert "Model in folder 'test_folder'" in message
+    assert "missing_model.safetensors" in message
+    assert "Searched in:" in message
+    assert first_dir in message
+    assert second_dir in message
+
+
+def test_get_full_path_or_raise_mentions_legacy_mapping(clear_folder_paths):
+    with pytest.raises(FileNotFoundError) as exc_info:
+        folder_paths.get_full_path_or_raise("clip", "missing_encoder.safetensors")
+
+    message = str(exc_info.value)
+    assert "Model in folder 'clip' (mapped to 'text_encoders')" in message
+    assert os.path.join(folder_paths.models_dir, "text_encoders") in message
+    assert os.path.join(folder_paths.models_dir, "clip") in message