package libfreetype6 2.8-0.2 failed to install/upgrade: trying to overwrite shared '/usr/share/doc/libfreetype6/changelog.Debian.gz', which is different from other instances of package libfreetype6:amd64

[Alexander Whatley]

I recently upgraded to 18.04, but this caused some problems with some text editors I am using. I tried to downgrade libfreetype to 2.8.0, which failed, and then I tried running fix-install in apt, but this also failed.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: libfreetype6 2.8-0.2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
AptOrdering:
 libfreetype6:amd64: Install
 NULL: ConfigurePending
Architecture: amd64
Date: Tue May 22 13:05:52 2018
Dependencies:
 gcc-8-base 8-20180414-1ubuntu2
 libc6 2.27-3ubuntu1
 libgcc1 1:8-20180414-1ubuntu2
 libpng16-16 1.6.34-1
 zlib1g 1:1.2.11.dfsg-0ubuntu2
DpkgTerminalLog:
 Preparing to unpack .../libfreetype6_2.8.1-2ubuntu2_amd64.deb ...
 Unpacking libfreetype6:amd64 (2.8.1-2ubuntu2) over (2.8-0.2) ...
 dpkg: error processing archive /var/cache/apt/archives/libfreetype6_2.8.1-2ubuntu2_amd64.deb (--unpack):
  trying to overwrite shared '/usr/share/doc/libfreetype6/changelog.Debian.gz', which is different from other instances of package libfreetype6:amd64
DuplicateSignature:
 package:libfreetype6:2.8-0.2
 Unpacking libfreetype6:amd64 (2.8.1-2ubuntu2) over (2.8-0.2) ...
 dpkg: error processing archive /var/cache/apt/archives/libfreetype6_2.8.1-2ubuntu2_amd64.deb (--unpack):
  trying to overwrite shared '/usr/share/doc/libfreetype6/changelog.Debian.gz', which is different from other instances of package libfreetype6:amd64
ErrorMessage: trying to overwrite shared '/usr/share/doc/libfreetype6/changelog.Debian.gz', which is different from other instances of package libfreetype6:amd64
InstallationDate: Installed on 2017-01-22 (485 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: freetype
Title: package libfreetype6 2.8-0.2 failed to install/upgrade: trying to overwrite shared '/usr/share/doc/libfreetype6/changelog.Debian.gz', which is different from other instances of package libfreetype6:amd64
UpgradeStatus: Upgraded to bionic on 2018-05-13 (9 days ago)

[Steve Langasek (vorlon)]

This is not an official Ubuntu version of the libfreetype6 package. Closing as not a bug.

You probably need to specifically install both the i386 and amd64 versions of the libfreetype6 package, from the same source, to fix this package installation failure.

[Goth Queen (artistbraab)]

@vorlon - Sorry to say, but this is the incorrect way to go forward.
Fact of the matter is that this indeed is a bug/ issue with the way 18.04 handles fonts.
Just closing it or setting it to invalid does NOT make it go away.
Nor does arguing on the "correct definition" of abhorrent, unproductive system behaviour.

Reports coming in of folks who in trust upgraded to 18.04 (LTS) do report (e.g. on git) all kind of issues with font rendering. The issue appears connected to libfreetype6 2.8.*, which seem to resolve with either upgrading to 2.9, or downgrading (if possible) to e.g. xenials 2.6 version.
Having installed Xubuntu 18.04 LTS myself this week on a precursor evaluation system (not VM) before applying to production boxen, I can confirm font handling is definitely off on 18.04 LTS. Sizes change all by themselves, and user settings are disregarded and reset upon reboot. These issues are so frequent and significant, that for us this marks 18.04 LTS currently as highly unstable and unreliable, thus holding any transitions from 16.04.