Description of change

In most cases, this change doesn’t require any changes to your code.
However, if your app was erroneously relying on the implicit
rebuilds you may see issues, which can be resolved by wrapping
any state change in a setState call.

Furthermore, this change slightly modified the shape of the
widget tree: Prior to this change,
the OverlayEntrys were wrapped in a Stack widget.
The explicit Stack widget was removed from the widget hierarchy.

Migration guide

If you’re seeing issues after upgrading to a Flutter version
that included this change, audit your code for missing calls to
setState. In the example below, assigning the return value of
Navigator.pushNamed to buttonLabel is
implicitly modifying the state and it should be wrapped in an
explicit setState call.

Code before migration:

class

FooState

extends

State

Foo

String