A problem has suddenly recently arisen such that simply by including the dependency in \'location\' in pubspec.yaml like e.g.
dependencies: flutter:
no need to change anything, a simple flutter build apk will solve the problem (if all the packages in pubspec.yaml are updated and error free)
flutter build apk
pubspec.yaml
this happens quite often when switching to a branch that has a completely different list of packages, flutter needs to build...