package mysql-server-5.7 5.7.11-0ubuntu6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Stephen Baker]

will not install

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.11-0ubuntu6
ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
Uname: Linux 4.4.0-21-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
Date: Fri Apr 22 22:22:57 2016
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2013-11-13 (891 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: ['debian-5.5.flag', 'performance_schema', 'ib_logfile0', 'mysql_upgrade_info', 'debian-5.7.flag', 'ibdata1', 'ib_logfile1', 'mysql']
ProcCmdline: BOOT_IMAGE=/vmlinuz-4.4.0-21-generic root=/dev/mapper/ubuntu--vg-root 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 5.7.11-0ubuntu6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-04-23 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.