Question: What happens if we have an object array and we get an error during the ufunc call? Such as:
```
a = np.array([1, 2], dtype=object)
b = np.array(['a'])
np.add.at(a, [0], b)
```
When api is needed, the inner loop can return an error I think? I m not sure how this is handled in the ufunc machinery, but I suspect we may need to add some magic in that case.