I'm on Big Sur beta. I have code like this:
Code Block swift List([treeRoot], children: \.children) { item in ...
Say the treeRoot (observed object) gets a new child. The view tries to re-render and fails:
2020-09-21 ... [General] NSOutlineView error inserting child indexes <_NSCachedIndexSet: 0x600000760000>[number of indexes: 1 (in 1 ranges), indexes: (3)] in parent 0x0 (which has 1 children).