package mysql-server-5.7 5.7.18-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[sameer soin]

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mysql-server-5.7 5.7.18-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-81.104-generic 4.4.67
Uname: Linux 4.4.0-81-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.1-0ubuntu2.6
Architecture: amd64
Date: Fri Jun 23 15:42:31 2017
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2015-09-27 (635 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
Logs.var.log.daemon.log:

MySQLConf.etc.mysql.mysql.conf.d.mysqld_safe_syslog.cnf:
 [mysqld_safe]
 syslog
MySQLVarLibDirListing: ['sys', 'mysql', 'ibdata1', 'mysql_upgrade_info', 'debian-5.7.flag', 'ib_logfile1', 'ib_buffer_pool', 'auto.cnf', 'performance_schema', 'ibtmp1', 'ib_logfile0', 'mujconnect']
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-4.4.0-81-generic root=UUID=2269f1a9-cc04-4175-82d4-6165438e9026 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.20
SourcePackage: mysql-5.7
Title: package mysql-server-5.7 5.7.18-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-07-29 (329 days ago)

[Christian Ehrhardt  (paelzer)]

Hi,
this appears to me as a known issue being worked on already - I dupped your report onto the main discussion so you can participate there.