FlutterでiOSをTestFlightにアップロードすると、 `ITMS-90338: Non-public API usage ` のエラーとなる問題

件名の通り
TstFlightにアップすると、下記のようなエラーメールが飛んできた

ITMS-90338: Non-public API usage - The app references non-public symbols in Frameworks/Flutter.framework/Flutter: _ptrace. If method names in your source code match the private Apple APIs listed above, altering your method names will help prevent this app from being flagged in future submissions. In addition, note that one or more of the above APIs may be located in a static library that was included with your app. If so, they must be removed. For further information, visit the Technical Support Information at http://developer.apple.com/support/technical/

原因は debugビルドをアップロードしてしまっているためなようで、

flutter build ios --release

アップロード前に、上記コマンドを実行したところ解決した