gradle task assembledebug failed code example

Example 1: gradle task assembledebug failed

I bet you will find the answer here. running on linux, windows, mac? 
Just check in
https://fluttercorner.com/flutter-app-stuck-at-running-gradle-task-assembledebug/

Example 2: Task 'assembleDebug' not found in project

You have to check, one by one each versions of your dependencies