Comment 13 for bug 1528583

Lars discovered an upgrade issue from Trusty to Xenial. We think the issue is that the Trusty apparmor does not support Unix domain socket rules, and during the upgrade the userspace tools are too old so mysqld fails to start.

I'm currently building a version in my test PPA that adds an apparmor dependency to ensure the new apparmor is configured first during the upgrade. Hopefully this will fix it for anyone upgrading from the latest Trusty HWE kernel. We're not sure about the Trusty release kernel yet.

We're doing this in ppa:racb/experimental so as not to affect any test results from those testing for us at the moment. If this works, then I'll update the main testing ppa:mysql-ubuntu/mysql-5.7 tonight (UK time). Please note that if you're already testing from the latter PPA then this may affect your results. If you need me to hold back from uploading because you need the old version for consistency across test runs, please let me know and I'll delay uploading.