Please do not split topics across several threads.
This makes following the conversation in the threads view very hard as the context of the other messages is missing.
If you have additional information either edit the original message or post to its thread.
Regarding the problem, that is not so much a Gradle question I'd say. You probably have to find out which kind of authentication BitBucket supports there and then whether the download task you are using (which is no Gradle core task) supports that authentication method and how.