Try:
flutter build web --profile --dart-define=Dart2jsOptimization=O0
See:
https://github.com/flutter/flutter/blob/720dff6a94bd054e82ec4bf84b5cb802bbc52ddd/packages/flutter_tools/lib/src/build_system/targets/web.dart#L238-L239
Try:
flutter build web --profile --dart-define=Dart2jsOptimization=O0
See:
https://github.com/flutter/flutter/blob/720dff6a94bd054e82ec4bf84b5cb802bbc52ddd/packages/flutter_tools/lib/src/build_system/targets/web.dart#L238-L239