package mysql-server-5.7 5.7.18-0ubuntu0.17.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Jakub Sawczuk]

After 16.10 to 17.04 upgrade

ProblemType: Package
DistroRelease: Ubuntu 17.04
Package: mysql-server-5.7 5.7.18-0ubuntu0.17.04.1
ProcVersionSignature: Ubuntu 4.10.0-20.22-generic 4.10.8
Uname: Linux 4.10.0-20-generic x86_64
ApportVersion: 2.20.4-0ubuntu4
Architecture: amd64
Date: Mon May 15 11:11:02 2017
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2017-03-08 (67 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.conf.d.mysql.cnf: [mysql]
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: ['mysql', 'ib_logfile0', 'crm1', 'ibtmp1', 'ibdata1', 'aff', 'crm2', 'ib_buffer_pool', 'tests', 'auto.cnf', 'ib_logfile1', 'sys', 'performance_schema', 'debian-5.7.flag']
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.10.0-20-generic root=UUID=0bacaca1-8728-412b-a202-4e20c189041c ro quiet splash
RelatedPackageVersions:
 dpkg 1.18.10ubuntu2
 apt 1.4
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.18-0ubuntu0.17.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to zesty on 2017-05-15 (0 days ago)

[Joshua Powers (powersj)]

From terminal log:

mysql_upgrade: Got error: 2002: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) while connecting to the MySQL server
Upgrade process encountered error and will not continue.
mysql_upgrade failed with exit status 11

[Joshua Powers (powersj)]

Marking this as a dup of LP: #1670629, if you have information that says otherwise, please feel free to add here.