v0.2.4

#15565 turned Dart 2 mode on by default.  To run in Dart 1 mode, you can still use --no-preview-dart-2.

    More details are available in the announcement.

#15537 removed SemanticsSortOrder. From now on traversal sorting is done among sibling nodes only.

    More details available in the announcement.

#15484 changed the meaning of the TextFormField initialValue constructor parameter.

    The TextFormField initialValue parameter no longer unconditionally initializes the text property of its TextEditingController. If you create a TextFormField and provide a controller, the initialValue must be null, which is now the default. If you’re providing a controller you can specify it’s initial text value with the TextEditingController text property.