I'm running Ubuntu 17.04, "zesty".

I need to install version 8 of Google Protocol Buffer.

I can find the package at https://packages.ubuntu.com/trusty/amd64/libprotobuf8/download

The instructions state that aptitude is the preferred way to download and install the package.

I've added the following line to the end of /etc/apt/sources.list:

deb http://mirrors.kernel.org/ubuntu/pool/main/p/protobuf trusty main 

Then I run aptitude:

$ sudo aptitude install libprotobuf8=libprotobuf8_2.5.0-9ubuntu1_amd64.deb

Unable to find a version "libprotobuf8_2.5.0-9ubuntu1_amd64.deb" for the package "libprotobuf8"

Unable to apply some actions, aborting



$ sudo aptitude install libprotobuf8=2.5.0-9ubuntu1

No packages will be installed, upgraded, or removed.

0 packages upgraded, 0 newly installed, 0 to remove and 6 not upgraded.

Need to get 0 B of archives. After unpacking 0 B will be used.

Using apt-get doesn't work either:

$ sudo apt-get install libprotobuf8=2.5.0-9ubuntu1

Reading package lists... Done

Building dependency tree       

Reading state information... Done

E: Can't find a source to download version '2.5.0-9ubuntu1' of 'libprotobuf8:amd64'

When I run sudo apt-get update

I see

...

Err:3 http://mirrors.kernel.org/ubuntu/pool/main/p/protobuf trusty/main amd64 Packages                                

  404  Not Found

...



W: The repository 'http://mirrors.kernel.org/ubuntu/pool/main/p/protobuf trusty Release' does not have a Release file.

N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.

N: See apt-secure(8) manpage for repository creation and user configuration details.

E: Failed to fetch http://mirrors.kernel.org/ubuntu/pool/main/p/protobuf/dists/trusty/main/binary-amd64/Packages  404  Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Nevertheless, /var/lib/dpkg/status shows:

Package: libprotobuf8

Status: install ok config-files

Section: libs

Installed-Size: 1083

Architecture: amd64

Multi-Arch: same

Source: protobuf

Version: 2.5.0-9ubuntu1

Config-Version: 2.5.0-9ubuntu1

Depends: libc6 (>= 2.14), libgcc1 (>= 1:4.1.1), libstdc++6 (>= 4.3), zlib1g (>= 1:1.1.4)

 This package contains the runtime library needed for C++ applications.

Homepage: https://code.google.com/p/protobuf/

Original-Maintainer: Robert S. Edmonds <[email protected]>

However I can't find libprotobuf.so.8 anywhere on the system.

What am I doing wrong?