[holidaylandmark] flutter pub get --no-example
Resolving dependencies...
The current Dart SDK version is 3.3.3.

Because flutter_icons 1.1.0 doesn't support null safety and no versions of flutter_icons match >1.1.0 <2.0.0, flutter_icons ^1.1.0 is forbidden.
So, because holidaylandmark depends on flutter_icons ^1.1.0, version solving failed.

The lower bound of "sdk: '>=2.0.0-dev.68.0 <3.0.0'" must be 2.12.0 or higher to enable null safety.
For details, see https://dart.dev/null-safety
exit code 1

Solution:

// run this command
flutter pub outdated

flutter pub outdated --mode=dev