Unhelpful error for duplicate page name when moving hierarchy between spaces

When moving a page hierarchy between spaces, if there is any page in the hierarchy being moved with the same name as a page in the target space, the move will abort with the message: "A descendent page shares the same title of another page in the selected space."

It should say which page(s) have duplicate names, and provide a way to resolve the problem (e.g. prompt to rename src pages with some suffix).