package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Nilesh G Pangul]

 post-installation script returned error exit status 1

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.20-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-98.121-generic 4.4.90
Uname: Linux 4.4.0-98-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
Date: Tue Nov 7 12:31:42 2017
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2016-04-09 (576 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
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: ['ib_logfile0', 'auto.cnf', 'debian-5.7.flag', 'sys', 'mysql', 'ib_logfile1', 'ib_buffer_pool', 'rescounter', 'performance_schema', 'ibdata1']
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-98-generic.efi.signed root=UUID=c0fdb7dd-2ecd-4f8f-9ed9-048641431f59 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.24
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.20-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-08-04 (459 days ago)
modified.conffile..etc.init.d.mysql: [deleted]

[Joshua Powers (powersj)]

From 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

[Joshua Powers (powersj)]

Hi and thanks for taking the time to file the bug report! Based on the log message it looks like this is a duplicate of LP: #1670629 and as such I am going to mark this as a duplicate. If you disagree please feel free to leave more details on this bug. Otherwise check out LP: #1670629 for a workaround.

Thanks!