Running my flutter flow app in test mode geerated a "build failure":
Because hu_cares depends on flutter_cache_manager 3.3.1 which depends on rxdart >=0.26.0 <0.28.0, rxdart >=0.26.0 <0.28.0 is required.
So, because hu_cares depends on rxdart ^0.28.0, version solving failed.