Before rB644e6c7a3e99ae1d43ed, `fill` was used in the error cases, but now `fill_indices` is used, which doesn't work when the span is empty (when only one output is used). The fix is just to check for that case.
Before rB644e6c7a3e99ae1d43ed, `fill` was used in the error cases, but now `fill_indices` is used, which doesn't work when the span is empty (when only one output is used). The fix is just to check for that case.