package gcc-4.9-base 4.9.2-10ubuntu13 [modified: usr/share/doc/gcc-4.9-base/changelog.Debian.gz usr/share/doc/gcc-4.9-base/copyright] failed to install/upgrade: trying to overwrite shared '/usr/share/doc/gcc-4.9-base/changelog.Debian.gz', which is different from other instances of package gcc-4.9-base:i386

[Greg]

After upgrade from 14.10 to 15.04 when installing upgraded packages ubuntu came up with too many broken packages and fialures. There is a bug in the upgrade which does not allow smooth upgrade. Bug in the grub also.The gcc was only one bug of many encountered.

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: gcc-4.9-base 4.9.2-10ubuntu13 [modified: usr/share/doc/gcc-4.9-base/changelog.Debian.gz usr/share/doc/gcc-4.9-base/copyright]
ProcVersionSignature: Ubuntu 3.19.0-30.34-generic 3.19.8-ckt6
Uname: Linux 3.19.0-30-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.5
AptOrdering:
 gcc-4.9-base: Install
 gcc-4.9-base: Configure
 gcc-4.9-base: Configure
 NULL: ConfigurePending
Architecture: amd64
Date: Tue Oct 20 10:48:12 2015
Dependencies:

DpkgTerminalLog:
 Preparing to unpack .../gcc-4.9-base_4.9.2-10ubuntu13_i386.deb ...
 Unpacking gcc-4.9-base:i386 (4.9.2-10ubuntu13) over (4.9-20140406-0ubuntu1) ...
 dpkg: error processing archive /var/cache/apt/archives/gcc-4.9-base_4.9.2-10ubuntu13_i386.deb (--unpack):
  trying to overwrite shared '/usr/share/doc/gcc-4.9-base/changelog.Debian.gz', which is different from other instances of package gcc-4.9-base:i386
DuplicateSignature: package:gcc-4.9-base:4.9.2-10ubuntu13 [modified: usr/share/doc/gcc-4.9-base/changelog.Debian.gz usr/share/doc/gcc-4.9-base/copyright]:trying to overwrite shared '/usr/share/doc/gcc-4.9-base/changelog.Debian.gz', which is different from other instances of package gcc-4.9-base:i386
ErrorMessage: trying to overwrite shared '/usr/share/doc/gcc-4.9-base/changelog.Debian.gz', which is different from other instances of package gcc-4.9-base:i386
InstallationDate: Installed on 2015-10-18 (1 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Beta amd64 (20150417.1)
RelatedPackageVersions:
 dpkg 1.17.25ubuntu1
 apt 1.0.9.7ubuntu4.1
SourcePackage: gcc-4.9
Title: package gcc-4.9-base 4.9.2-10ubuntu13 [modified: usr/share/doc/gcc-4.9-base/changelog.Debian.gz usr/share/doc/gcc-4.9-base/copyright] failed to install/upgrade: trying to overwrite shared '/usr/share/doc/gcc-4.9-base/changelog.Debian.gz', which is different from other instances of package gcc-4.9-base:i386
UpgradeStatus: No upgrade log present (probably fresh install)