Adventures & experiences in contemporary technology
Not so long ago, I got the above message while running sudo apt upgrade on an Ubuntu Server system. This was not the first time that this kind of thing happened to me, so I started searching the web for a solution. You do get to see complaints about advertising, but these are never useful.
Accordingly, here are some possible ways of remediating the situation:
sudo systemctl mask apt-news.service
sudo systemctl mask esm-cache.service
sudo mv /etc/apt/apt.conf.d/20apt-esm-hook.conf
/etc/apt/apt.conf.d/20apt-esm-hook.conf.disabled
ubuntu-advantage-tools package, which contains the /etc/apt/apt.conf.d/20apt-esm-hook.conf file.ubuntu-pro-client package.In my case, it may have been the penultimate option on the list that I chose. In any case, I was rid of the unwanted message.
Recently, a message appear on some web servers that I have that exhorted me to upgrade to Ubuntu 22.04.1 using the do-release-upgrade command. In the interests of remaining current, I did just that to get another message, one like the following:
The upgrade needs a total of [amount of space with units] free space on disk `/boot`.
Please free at least an additional [amount of space with units] of disk space on `/boot`.
Empty your trash and remove temporary packages of former installations
using `sudo apt-get clean`.
Using sudo apt-get clean did not resolve the problem so the advice given was of no use. The actual problem was that there were too many old kernels cluttering up /boot and searching around the web provided that wisdom. What also came up was a single command for fixing the problem. However, removing the wrong kernel can trash a system so I took a more cautious approach. First, I listed the kernels to be removed and checked that they did not include the currently running one. This was done with the following command (broken up over several lines for clarity using the backslash character to denote continuation) and running uname -r found the details of the running kernel:
dpkg -l linux-{image,headers}-"[0-9]*" \
| awk '/ii/{print $2}' \
| grep -ve "$(uname -r \
| sed -r 's/-[a-z]+//')"
The dpkg command listed the installed kernels with awk, grep and sed filtering out unwanted sections of the text. The awk command takes the tabular output from dpkg and turns it into a list. The -v switch on the grep command gets the lines that do not match the search expression created by the sed command, while the -e switch makes grep look for patterns. The sed command removes all letters from the output of the uname command, where the -r switch produces the kernel release details, to leave on the release number of the current kernel. On being satisfied that nothing untoward would happen, the full command below (also broken up over several lines for clarity using the backslash character to denote continuation) could be executed.
sudo apt purge $(dpkg -l linux-{image,headers}-"[0-9]*" \
| awk '/ii/{print $2}' \
| grep -ve "$(uname -r \
| sed -r 's/-[a-z]+//')")
This apt to purge the unwanted kernels, thus freeing up enough space for the upgrade to continue. That happened without significant incident though there were some remediations needed on the PHP side to get the website working smoothly again.
The Flatpak concept offers a useful way of getting the latest version of software like LibreOffice or GIMP on Linux machines because repositories are managed conservatively when it comes to the versions of included software. Ubuntu has Snaps, which are similar in concept. Both options bundle dependencies with the packaged software so that its operation can use later versions of system libraries that what may be available with a particular distribution.
However, even Flatpak depends on what is available through the repositories for a distribution as I found when a software update needed a version of the tool. The solution was to add PPA using the following command and agreeing to the prompts that arise (answering Y, in other words):
sudo add-apt-repository ppa:alexlarsson/flatpak
With the new PPA instated, the usual apt commands were used to update the Flatpak package and continue with the required updates. Since then, all has gone smoothly as expected.
Having moved beyond the slow response and larger memory footprint of Firefox ESR, I am using Firefox Developer Edition in its place even if it means living without a status bar at the bottom of the window. Hopefully, someone will create an equivalent of the old add-on bar extensions that worked before the release of Firefox Quantum.
Firefox Developer Edition may be pre-release software with some extras for web developers like being able to to drill into an HTML element and see its properties but I am finding it stable enough for everyday use. It is speedy too, which helps, and it has its own profile so it can co-exist on the same machine as regular releases of Firefox like its ESR and Quantum variants.
Installation takes a little added effort though and there are various options available. My chosen method involved Ubuntu Make. Installing this involves setting up a new PPA as the first step and the following commands added the software to my system:
sudo add-apt-repository ppa:ubuntu-desktop/ubuntu-make
sudo apt-get update
sudo apt-get install ubuntu-make
With the above completed, it was simple to install Firefox Developer edition using the following command:
umake web firefox-dev
Where things got a bit more complicated was getting entries added to the Cinnamon Menu and Docky. The former was sorted using the cinnamon-menu-editor command but the latter needed some tinkering with my firefox-developer.desktop file found in .local/share/applications/ within my user area to get the right icon shown. Discovering this took me into .gconf/apps/docky-2/Docky/Interface/DockPreferences/%gconf.xml where I found the location of the firefox-developer.desktop that needed changing. Once this was completed, there was nothing else to do from the operating system side.
Within Firefox itself, I opted to turn off warnings about password logins on non-https websites by going to about:config using the address bar, then looking for security.insecure_field_warning.contextual.enabled and changing its value from True to False. Some may decry this but there are some local websites on my machine that need attention at times. Otherwise, Firefox is installed with user access so I can update it as if it were a Windows or MacOS application and that is useful given that there are frequent new releases. All is going as I want it so far.
This is how I got around problem that occurred when I was updating a virtualised Ubuntu 16.04 instance that I have. My usual way to do this is using apt-get or apt from the command line and the process halted because a pre-removal script for the upgrade of avahi-dnsconf failed. The cause was its not disabling the avahi daemon beforehand so I need to execute the following command before repeating the operation:
sudo systemctl disable avahi-daemon
Once the upgrade had completed, then it was time to re-enable the service using the following command:
sudo systemctl enable avahi-daemon
Ideally, this would completed without such manual intervention and there is a bug report for the unexpected behaviour. Hopefully, it will be sorted soon but these steps will fix things for now.
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.
When I upgraded to Ubuntu GNOME 13.10 and went for the 64-bit variant, I tried a previously tried and tested approach for installing Nightingale that used a PPA only for it not to work. At that point, the repository had not caught up with the latest Ubuntu release (it has by the time of writing) and other pre-compiled packages would not work either. However, there was one further possibility left and that was downloading a copy of the source code and compiling that. My previous experiences of doing that kind of thing have not been universally positive so it was not my first choice but I gave it a go anyway.
In order to get the source code, I first needed to install Git so I could take a copy from the version controlled repository and the following command added the tool and all its dependencies:
sudo apt-get install git autoconf g++ libgtk2.0-dev libdbus-glib-1-dev libtag1-dev libgstreamer-plugins-base0.10-dev zip unzip
With that lot installed, it was time to checkout a copy of the latest source code and I went with the following:
git clone https://github.com/nightingale-media-player/nightingale-hacking.git
The next step was to go into the nightingale-hacking sub-folder and issue the following command:
./build.sh
That should produce a sub-directory named nightingale that contains the compiled executable files. If this exists, it can be copied into /opt. If not, then create a folder named nightingale under /opt using copy the files from ~/nightingale-hacking/compiled/dist into that location. Ubuntu GNOME 13.10 comes with GNOME Shell 3.8, the next step took a little fiddling before it was sorted: adding an icon to application menu or dashboard. This involved adding a file called nightingale.desktop in /usr/share/applications/ with the following contents:
[Desktop Entry]
Name=Nightingale
Comment=Play music
TryExec=/opt/nightingale/nightingale
Exec=/opt/nightingale/nightingale
Icon=/usr/share/pixmaps/nightingale.xpm
Type=Application
X-GNOME-DocPath=nightingale/index.html
X-GNOME-Bugzilla-Bugzilla=Nightingale
X-GNOME-Bugzilla-Product=nightingale
X-GNOME-Bugzilla-Component=BugBuddyBugs
X-GNOME-Bugzilla-Version=1.1.2
Categories=GNOME;Audio;Music;Player;AudioVideo;
StartupNotify=true
OnlyShowIn=GNOME;Unity;
Keywords=Run;
Actions=New
X-Ubuntu-Gettext-Domain=nightingale
[Desktop Action New]
Name=Nightingale
Exec=/opt/nightingale/nightingale
OnlyShowIn=Unity
It was created from a copy of another *.desktop file and the categories in there together with the link to the icon were as important as the title and took a little tinkering before all was in place. Also, you may find that /opt/nightingale/chrome/icons/default/default.xpm needs to be become /usr/share/pixmaps/nightingale.xpm using the cp command before your new menu entry gains an icon to go with it. While the steps that I describe here worked for me, there is more information on the Nightingale wiki if you need it.
Installing the latest version of Citrix Receiver (13.0 at the time of writing) on 64-bit Ubuntu should be as simple as downloading the required DEB package and double-clicking on the file so that Ubuntu Software Centre can work its magic. Unfortunately, the 64-bit DEB file is faulty so that means that the Ubuntu community how-to guide for Citrix still is needed. In fact, any user of Linux Mint or another distro that uses Ubuntu as its base would do well to have a look at that Ubuntu link.
For sake of completeness, I still am going to let you in on the process that worked for me. Once the DEB file has been downloaded, the first task is to creating a temporary folder where the DEB file’s contents can be extracted:
mkdir ica_temp
With that in place, it then is time to do the extraction and it needs two commands with the second of these need to extract the control file while the first extracts everything else.
sudo dpkg-deb -x icaclient- ica_temp
sudo dpkg-deb --control icaclient- ica_temp/DEBIAN
It is the control file that has been the cause of all the bother because it refers to unavailable dependencies that it really doesn’t need anyway. To open the file for editing, issue the following command:
sudo gedit ica_temp/DEBIAN/control
Then change line 7 (it should begin with Depends:) to: Depends: libc6-i386 (>= 2.7-1), lib32z1, nspluginwrapper. There are other software packages in there that Ubuntu no longer supports and they are not needed anyway. With the edit made and the file saved, the next step is to build a new DEB package with the corrected control file:
dpkg -b ica_temp icaclient-modified.deb
Once you have the package, the next step is to install it using the following command:
sudo dpkg -i icaclient-modified.deb
If it fails, then you have missing dependencies and the following command should sort these before a re-run of the above command again:
sudo apt-get install libmotif4:i386 nspluginwrapper lib32z1 libc6-i386
With Citrix Receiver installed, there is one more thing that is needed before you can use it freely. This is to put Thawte security certificate files into /opt/Citrix/ICAClient/keystore/cacerts. What I had not realised until recently was that many of these already are in /usr/share/ca-certificates/mozilla and linking to them with the following command makes them available to Citrix receiver:
sudo ln -s /usr/share/ca-certificates/mozilla/* /opt/Citrix/ICAClient/keystore/cacerts/
Another approach is to download the Thawte certificates and extract the archive to /tmp/. From there they can be copied to /opt/Citrix/ICAClient/keystore/cacerts and I copied the Thawte Personal Premium certificate as follows:
sudo cp /tmp/Thawte Root Certificates/Thawte Personal Premium CA/Thawte Personal Premium CA.cer /opt/Citrix/ICAClient/keystore/cacerts/
Until I found out about what was in the Mozilla folder, I simply picked out the certificate mentioned in the Citrix error message and copied it over like the above. Of course, all of this may seem like a lot of work to those who are non-tinkerers and I have added a repaired 64-bit DEB package that incorporates all of the above and should not need any further intervention aside from installing it using GDebi, Ubuntu’s Software Centre, dpkg or anything else that does what’s needed.
Ever since the Songbird project concentrated its efforts to support only Windows and OS X, the Firefox-based music player has been absent from a Linux user’s world. However, the project is open source and a fork called Nightingale now fulfils the same needs. Intriguingly, it too is available for Windows for OS X users so I am left wondering why that overlap has happened. However, Songbird also is available as a web app and as an app on both Android and iOS while Nightingale sticks to being a desktop application.
To add it to Ubuntu, you need to set up a new repository. That can be done using the Software Centre but issuing a command in a terminal can be so much quicker and cleaner so here it is:
sudo add-apt-repository ppa:nightingaleteam/nightingale-release
Apart from entering your password, there will be prompt to continue by pressing the carriage return key or cancelling with CTRL + C. For our purposes, it is the first action that’s needed and once that’s done the needful, you can execute the following command:
sudo apt-get update && sudo apt-get install nightingale
This is in two parts: the first updates the repositories on your system and second actually installs the software. When that is complete, you are ready run Nightingale and, with the repository, staying up to date is not chore either. In fact, using the above commands brings another advantage and it is that they should in any Ubuntu derivatives such as Linux Mint.
My Epson Perfection 4490 Photo scanner has been in my possession for a while now and its impossible to justify any replacement given that it both works well and digital photography has taken over from its film predecessor for me. Every time I go installing an operating system afresh, I need to reinstate it again and last year’s installation of Ubuntu GNOME Remix 12.04 only saw me do the deed recently. When I did so, it was brought back to me that I’d never gone and documented on here how this was done. Given that I sometimes use this place as a repository of stuff to which I need to refer again in the future, it seemed remiss of me so here it is for you all.
Though I had XSane and SimpleScan already installed on the system, Sane wasn’t on there so I went and added it and a few other extras using the following command:
sudo apt-get install sane sane-utils libsane-extras
Then, it was onto the Epson website for their Perfection 4490 Photo Linux drivers since Sane’s support for this scanner seemingly remains incomplete even though it pre-dates my move to Linux in 2007. Three files were needed and the following commands install them (depending on when you do this, the file names may be different so just change them to whatever they are for you; it can be done with a single command too but there is not enough girth for that here):
sudo dpkg -i iscan-data_1.22.0-1_all.deb
sudo dpkg -i iscan_2.29.1-5~usb0.1.ltdl7_i386.deb
sudo dpkg -i iscan-plugin-gt-x750_2.1.2-1_i386.deb
With those in place, there was one other task that needed doing so that scanning could be done without resorting to running scanning software using sudo privileges. To free up the access to a normal user account, I needed a HAL device information file. These normally are in /usr/share/hal/fdi/ but they change every time an installation so any modifications that you may make are going to be lost. Therefore, there is no point modifying either /usr/share/hal/fdi/preprobe/10osvendor/20-libsane.fdi or /usr/share/hal/fdi/preprobe/10osvendor/20-libsane-extras.fdi where scanner information usually is to be found.
The first task in creating an fdi file was to issue the lsusb command and look for a line corresponding to my scanner. This is the one that I got:
Bus 001 Device 004: ID 04b8:0119 Seiko Epson Corp. Perfection 4490 Photo
From this, I gleaned the manufacturer ID and model ID as 04b8 and 0119, respectively. These are needed later on. Next I needed to create the hal/fdi/preprobe/ folder structure under /etc since it was there. Then, I created epson4490photo.fdi in the bottom folder of the tree (/etc/hal/fdi/preprobe/epson4490photo.fdi) as follows:
cd /etc/hal/fdi/preprobe/ && sudo touch epson4490photo.fdi
Then, I edited the new file using the following command:
gksu gedit epson4490photo.fdi &
When open, I added in the following text:
<?xml version="1.0" encoding="UTF-8"?>
<deviceinfo version="0.2">
<device>
<match key="info.subsystem" string="usb">
<!-- Epson Perfection 4490 Photo -->
<match key="usb.vendor_id" int="0x04b8">
<match key="usb.product_id" int="0x0119">
<append key="info.capabilities" type="strlist">scanner</append>
<merge key="scanner.access_method" type="string">proprietary</merge>
</match>
</match>
</match>
</device>
</deviceinfo>
It’s all in XML so the place to look is immediately beneath the scanner name comment. The int attributes of the two match elements immediately following the comment line are populated using the information from the lsusb command output with 0x prefixing both the manufacturer and model identifiers. The element with a key attribute of usb.vendor_id is the former and that with a key attribute of usb.product_id is the latter. With epson4490photo.fdi saved, I rebooted the machine to restart HAL and all was as I wanted it to be apart maybe from XSane making complaints that seemed not to be of any actual consequence. With Epson’s Image Scan! and Simple Scan on the PC, there’s no need to be bothered with those messages. Choice is good when you have it, especially when you have expended some effort to get that far.