Flutter エラー時の対処法いろいろ
fatal error: module 'cloud_firestore' not found
が出たとき
https://github.com/FirebaseExtended/flutterfire/issues/1979
fatal error: module 'cloud_firestore' not found
が出たときhttps://github.com/FirebaseExtended/flutterfire/issues/1979
fatal error: 'UserAgent.h' file not found
が出たとき