Ruby on Rails Arch Linux Basic Instal

I have been playing with Ruby on Rails for a while after completing a Coursera based SaaS course recently. While undertaking the course I worked on an Ubuntu VM which was provided by the course. However, as in all things I hack around with on Linux I really wanted to set up a basic Rails development environment on my main Arch Linux machine.

While the guide on the Arch wiki was fine when I reached the point of testing my environment I got the following output in bash ....

/usr/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes.

A quick hunt around the forums did not help me!

Following the link in the above error message I read up on execjs and found that you need a supported runtime. I opted for therubyracer, an implementation of the Google v8 javascript runtime.

In bash I ran gem install therubyracer which installed the runtime. I then added the following line to my test applications Gemfile :

gem 'therubyracer', :require => 'v8'

Running rails server now served up my test app on the default port (using WEBrick).

Arch Linux glibc Update

Arch Linux has made a rather big change to the file system recently and has moved the files in the /lib directory to the /usr/lib directory and /lib is now a symlink to usr/lib. You can get an overview of the change here and here. Both of these pages give instructions and possible issue resolutions for most case's.

However, as searching the Arch Forums on glibc will show, the resolutions outlined in the above documents do not always work. There are a large number of users that have had problems due to various files that are left in the /lib directory. To quote Zamboniman from the Arch Forums "This has been one of the more frustrating upgrades in my history with Arch." After running pacman -Syu recently I discovered I was one of these people!

I have now resolved my issue and wanted to detail it incase it is any help to anyone else still struggling with the issue. For a little background I am running Arch 64bit.

NOTE DO NOT USE --force WITH pacman IN ANY FORM TO RESOLVE THIS ISSUE AND DO NOT DELETE OR MOVE ANY FILES MANUALLY.

First, I followed the recommended update method and ran pacman -Syy and then pacman -Syu --ignore glibc. This brought the system up to date and I then ran pacman -Su which will update glibc. However, like so many others, I got the following error output :

error: failed to commit transaction (conflicting files) glibc: /lib exists in filesystem

This, apparently, is caused by files remaining in the /lib directory. As per a number of the suggested solutions I then ran find /lib -exec pacman -Qo -- {} + which lists who owns the files left in the /lib directory. As recommended in one forum post I started to look for files not owned by glibc. There was one file and that was lib32-glibc. A lot of the solutions suggested at this point to just delete the file or uninstall the program that it is installed by however, looking at the file version (2.15-10) I noticed that there was a newer version available. The file is installed from the Multilib repository and I was at a loss as to how it was not being updated. After a little more digging I found that the Multilib repository was commented out in the /etc/pacman.conf file. I uncommented the repository entry in the file and ran pacman -Syy and then pacman -Syu --ignore glibc and then ran pacman -Su.

This all appeared to work. As a final check I ran ls -ld /lib which should output lrwxrwxrwx 1 root root 7 Jul 7 11:09 /lib -> usr/lib which denotes that everything has worked.

This solution will probably not fix everyone's issue with regard to this update and the links below are to forum threads that helped me track down the solution to my problem

• https://bbs.archlinux.org/viewtopic.php?id=145006&p=1
• https://wiki.archlinux.org/index.php/DeveloperWiki:usrlib
• https://bbs.archlinux.org/viewtopic.php?pid=1129890 - This thread contains Zamboniman's excellent advice which appears to have helped a number of people with slightly different issues to mine.
• https://bbs.archlinux.org/viewtopic.php?id=109765 - Multilib related.

Now, to get on with playing with KDE 4.9!

Arch Linux Qt Package Issue (KDE)

For the first time in all the time I have been using Arch I have experience my first major package breakage.

The night before last I ran pacman -Syu and one the packages upgraded was the Qt package. It was upgraded to qt-4.8.1-2. Next time I booted up I was getting a KDE Crash dialog appear noting an error with KRunner. Trying to run krunner from the shell I was presented with a host of errors.

A quick search of the Arch forums I found this post reporting similar problems. Following the advice in the post I downgraded the Qt package and my problems where resolved.

To find out if you can downgrade your package you will need to search the /var/cache/pacman/pkg directory to ensure you have a package to downgrade to. If you do then you can run pacman -U /var/cache/pacman/pkg/qt-4.8.0-6-x86_64.pkg.tar.xz (or whatever version you have). If you can not find an earlier package in your cache then you will have to refer here (the Arch wiki) which will provide further details.

(I should mention that I am running 64bit although I have no idea if this effects 32bit).

Arch Linux - i3 Graphics Setup

Gonzo has been reborn!

My trusty old Thinkpad has finally died and so I have brought a Fujitsu A531 to replace it. Its not a bad spec for the money I paid (i3 2.2, 8gb, 750gb HDD all for £419).

I have just installed Arch 64 bit on it and had KDE up and running in less than an hour and a half. The first thing I noticed was the graphics acceleration was not enabled and I seemed to be suffering poor framerates. I found that by adding a file called 20-intel.conf to the /etc/X11/xorg.conf.d directory and adding the following solved my issues :


Section "Device"
Identifier "Card0"
Driver "intel"
Option "DRI" "true"
Option "SwapbuffersWait" "false"
EndSection


Reboot and 3D effects and a good framerate where restored.

Arch Linux - LibreOffice Displaying Non English

When LibreOffice was first released I instantly installed it (via pacman) on Arch Linux. Having read lots about the grand work the project was doing to finally bring the project upto date since forking Open Office I was interested to see what they had achieved. I was quite impressed.

I don't do a lot of document based work on my Arch laptop (and there have been a number of updates since I last used it) but I went to type up a letter for the wife tonight and fired up LibreOffice and found the UI was rendering in what appeared to be Russian (which I do not read or write).

After a bit of digging about it appeared I made a fatal error in installing the libreoffice-uk language pack. Turns out that is the Ukrainian language pack ... oops!

It turns out that I am not alone in making this assumption and if you happen to hit this issue and you actually need English and not Ukrainian then install the libreoffice-en-GB language pack and all will be well (and readable) again.

Arch KDE SC 4.7 Missing KDM Background

If after upgrading KDE to 4.7 on Arch you notice that your KDM theme is missing you need to run the following:

pacman -S kde-wallpapers

It turns out the KDM default theme use's an image from the KDE Wallpapers package which has been split out on it's own from 4.7.

Arch Linux Zope Interface Update Issue

The issue is old now, I have ignored it for about a month of pacman -Syu but in updating to KDE 4.7 tonight I hit it again.

If you pacman -Syu and get

error: failed to commit transaction (conflicting files)
python2-zope-interface: /usr/lib/python2.7/site-packages/zope.interface-3.6.3-py2.7.egg-info/ exists in filesystem

The you need to go to this page and follow the two simple commands.

It would appear to be a simple bug in pacmans conflict resolution handling. It had to happen sometime I guess!!

Arch wicd upgrade

Just ran a system update on my Arch install and it failed to commit due to some changes in the wicd package structure.

This post on the forums has a couple of solutions but I ended up forcing an upgrade (-f) on the wicd package and the updated as usual and all was well with my world once again.