If toytoolkit tries to load a cursor that does not exist, it will complain and presumably continue with no image for that cursor. This likely leads to the cursor disappearing when attempting to use a cursor not found. It would be much better, if in addition to complaining, toytoolkit would fall back to a cursor that is obviously wrong.
This issue was encountered with the Weston DND demo, when no real cursor theme was available, and the new dnd cursors are not found in libwayland-cursor.
Should the fallback cursor be provided by toytoolkit itself, or by libwayland-cursor default cursors, or by picking some default cursor already provided by libwayland-cursor?