ERROR: Can’t find the archive-keyring

When I recently did my usual system update for the stable version Ubuntu GNOME, there were some updates pertaining to apt and the process failed when I executed the following command:

sudo apt-get upgrade

Usefully, some messages were issued and here’s a flavour:

Setting up apt (0.9.9.1~ubuntu3.1) …
ERROR: Can’t find the archive-keyring
Is the ubuntu-keyring package installed?
dpkg: error processing apt (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
apt
E: Sub-process /usr/bin/dpkg returned an error code (1)

Some searching on the web revealed that the problem was that there were no files in /usr/share/keyring when there should have been and I had not removed them myself so I have no idea how they disappeared. Various remedies were tried and any that needed software installed were non-starters because apt was disabled by the lack of keyring files. The workaround that restored things for me was to take a copy of the files in /usr/share/keyring from an Ubuntu GNOME 14.04 installation in a VirtualBox VM and copy them in to the same location in its Ubuntu GNOME 13.10 host. For those without such resources, I have packaged them in a zip file below. Other remedies like Y PPA also were suggested where I was reading but that software package needed installing beforehand so it was little use to me when the likes of Synaptic were disabled. If there are other remedies that do not involve an operating system re-installation, I would like to know about them too as well as possible causes for the file loss in the first place and how to avoid these.

Ubuntu Keyrings

Ubuntu 10.10 and Citrix

Many of us with the opportunity to work from home will have met up with logging via a Citrix server. With that in mind, I set to getting an ICA client going on my main Ubuntu box at home. There is information scattered about the web in the form of question on the Ubuntu forum and a step-by-step guide by Liberian Geek. To summarise the process that I followed here, you have to download a copy of the Citrix Receiver installer for Linux from the company’s website. There, you’ll see DEB and RPM packages along with a tarball for other systems. The latter needs a bit more work so I got the x86 DEB package and installed that in the usual way using Ubuntu’s Software Centre to do the installation following the download. Needing to start the Citrix connection via a browser session meant that a browser restart was needed too. That wasn’t the end of the leg work because Thawte certificate errors were to stop me in my tracks until I downloaded their root certificates from their website. Once the zip file was on my PC, I extracted it and copied the required certificate (Thawte Server CA.cer from the thawte Server CA directory) to /usr/lib/ICAClient/keystore/cacerts on my system; it helped that the error message had told me which was the one I needed from the collection in the zip file. With that matter addressed, the connection happened without a glitch and I was able to get to working without recourse to a Windows virtual machine. For once, Linux wasn’t to be excluded from one of the ways of using computers that has been getting more prevalent these days.

Update 2012-04-14: On an equivalent installation on Linux Mint Debian Edition, I found that the installation location for the certificate had moved to /opt/Citrix/ICAClient/keystore/cacerts. This was for the 64-bit edition.

Update 2012-12-17: The above applied to an installation of version 12.10 on 32-bit Ubuntu GNOME Remix too.