构建失败

[sis-tangyuan]

Error: A value of type 'Future Function(Uri, String, String)?' can't be assigned to a variable of type 'Future Function(Uri, String, String?)?' because 'String?' is nullable and 'String' isn't.

• 'Future' is from 'dart:async'.
• 'Uri' is from 'dart:core'.
  nativeHttpClient.authenticate = f;
  Error: A value of type 'Future Function(String, int, String, String)?' can't be assigned to a variable of type 'Future Function(String, int, String, String?)?' because 'String?' is nullable and 'String' isn't.
• 'Future' is from 'dart:async'.
  nativeHttpClient.authenticateProxy = f;

[cnryb]

kraken 还没有对 flutter 2.5.x 进行支持，请使用 flutter 2.2.x 进行构建测试。
关于 kraken 对 flutter 2.5.x 的支持进展，请关注 openkraken/kraken#703