Avoid crash of SC2 if no templates are detected after clustering

src/spikeinterface/sorters/internal/spyking_circus2.py

@@ -382,7 +382,8 @@ def _run_from_folder(cls, sorter_output_folder, params, verbose):
                     sorting.save(folder=curation_folder)
                     # np.save(fitting_folder / "amplitudes", guessed_amplitudes)
 
-                sorting = final_cleaning_circus(recording_w, sorting, templates, **merging_params, **job_kwargs)
+                if sorting.get_non_empty_unit_ids().size > 0:
+                    sorting = final_cleaning_circus(recording_w, sorting, templates, **merging_params, **job_kwargs)
 
                 if verbose:
                     print(f"Kept {len(sorting.unit_ids)} units after final merging")

src/spikeinterface/sortingcomponents/matching/main.py

@@ -46,6 +46,9 @@ def find_spikes_from_templates(
     method_class = matching_methods[method]
     node0 = method_class(recording, **method_kwargs)
     nodes = [node0]
+    assert "templates" in method_kwargs, "You must provide templates in method_kwargs"
+    if len(method_kwargs["templates"].unit_ids) == 0:
+        return np.zeros(0, dtype=node0.get_dtype())
 
     spikes = run_node_pipeline(
         recording,