TypeError: constructor returned NULL

Seen in a contributor's Log for Ubuntu 24.04 and Sugar 0.21;

```
Traceback (most recent call last):
  File "/home/baltazar/Activities/Paint.activity/Area.py", line 929, in flood_fill
    cursor = Gdk.Cursor.new_from_name(display, 'paint-bucket')
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: constructor returned NULL
```