What does 'Bad File descriptor' mean for Flutter ios?

Question

I keep getting 'Bad file descriptor' errors for Flutter on iOS production builds. According to Sentry, they come from the post request I am sending to the backend.

Code of post function:

            static Future<dynamic> post(
String endPoint, {
Map<String, dynamic>? body,
 }) async {
var uri = Uri.parse(_apiUrl + endPoint);
print('post: $uri');
print('body: $body');

http.Response response;

response = await http.post(
  uri,
  body: json.encode(body),
  headers: {
    'Content-type': 'application/json',
  },
);

// Check response: throws exception if not successful
_checkResponse(response);

return json.decode(response.body);
 }

 static void _checkResponse(http.Response res) {
print('_checkResponse code: ${res.statusCode}');

if (res.statusCode != 200) {
  var body = json.decode(res.body);
  print('body of error is : ${body['error']}');
  throw NetworkException(
    ExceptionError.fromMap(body['error']),
    statusCode: res.statusCode,
  );
}

}