debugDoingThisLayoutWithCallback property

Whether invokeLayoutCallback for this render object is currently running.

Layout callbacks are a special part of this render object's layout phase: they are allowed to mutate child lists and dirty render subtrees while the callback is executing. This flag lets debug-only assertions distinguish that special callback phase from the regular performLayout body.

This does not imply that a widget rebuild is currently in progress. A layout callback can trigger rebuild work by mutating the render or element tree, but this flag only describes the synchronous callback passed to invokeLayoutCallback.