我在Gitlab上为Flutter应用程序创建了一个配置项，初始化gradle时出现错误。
错误：
$ flutter packages get
Running "flutter packages get" in codingroomevents... 8.5s
$ flutter build apk --release
Initializing gradle...
ProcessException: Process "/builds/user/codingroomevents/android/gradlew" exited abnormally:
Downloading https://services.gradle.org/distributions/gradle-4.10.2-all.zip
Exception in thread "main" java.net.SocketException: Network is unreachable (connect failed)
谢谢。