package mysql-server-5.7 5.7.12-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[ibob63]

This bug has been consistently here from when I installed the beta version of Ubuntu 16:04.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.12-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6
Uname: Linux 4.4.0-18-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
Date: Mon Apr 25 14:26:06 2016
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2013-10-24 (913 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
MySQLConf.etc.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
MySQLConf.etc.mysql.conf.d.mysqldump.cnf:
 [mysqldump]
 quick
 quote-names
 max_allowed_packet = 16M
MySQLConf.etc.mysql.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
MySQLVarLibDirListing: ['ibdata1', 'ib_logfile0', 'xtrabackup_binary', 'bacula', 'debian-5.6.flag', 'debian-5.5.flag', 'performance_schema', 'mysql', 'ib_buffer_pool', 'printnode', 'wardington', 'mysql_upgrade_info', 'ib_logfile1', 'test', 'auto.cnf', 'xtrabackup_checkpoints', 'bloguk', 'debian-5.7.flag', 'backup-my.cnf', 'randomhacks', 'xtrabackup_logfile']
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-18-generic root=UUID=ed26a9e4-b9ed-42a0-ad85-f53643507246 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1
 apt 1.2.10ubuntu1
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.12-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-04-06 (19 days ago)