Install of mysql hangs on 16.04

See question and linked answer at http://serverfault.com/a/831169/15756, also comment 18 by Rocko on #1571865 @ https://bugs.launchpad.net/ubuntu/+source/mysql-5.7/+bug/1571865/comments/18, referenced by the blog post referenced by the answer to the serverfault question. He was asked to created a new bug but did not have the time - please regard this as the bug report.

1) lsb_release -rd:
Description: Ubuntu 16.04.2 LTS
Release: 16.04

2) apt-cache policy mysql-server:
mysql-server:
  Installed: 5.7.17-0ubuntu0.16.04.1
  Candidate: 5.7.17-0ubuntu0.16.04.1
  Version table:
 *** 5.7.17-0ubuntu0.16.04.1 500
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main i386 Packages
        100 /var/lib/dpkg/status
     5.7.11-0ubuntu6 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu xenial/main i386 Packages

3) I expected to be able to install mysql as part of a vagrant provisioning script without having to jump through Ubuntu specific hoops.

4) `apt-get install -y mysql-server mysql-client` hung and stalled my build pipeline until I added the line `(sleep 200; killall mysqld)&` to my provisioning script right before that line. This makes me very uncomfortable - I should never have to kill a setup task.