MariaDB 10.2 apt source repository for Ubuntu trusty, xenial, yakkety is corruppted, so we can't get MariaDB 10.2 source package anymore.
apt-get source succeeds.
apt-get source fails.
I've noticed this issue on Travis-CI.
Here is the build error log on it.
This issue is caused by empty metadata such as folows:
This error is not limited to above mirror only. I investigated some of other mirrors, but all of them contains same problems.