Who Says Penguins Can't Fly?

Today I finally succeeded to build KDE trunk (development version of KDE SC) after previously struggling with some Phonon-related problems. I decided to start from scratch, and while the overall process was quite smooth, I managed to hit some bumps along the way. Below I’ve shared my experience.

First I want to remind you that this isn’t a comprehensive guide to build KDE SC from SVN – you can find those on Techbase. I followed much of the Getting Started/Build/KDE4 guide to get started.

Introduction

I’ve found it easiest to build KDE trunk using a tool called kdesvn-build. From its Techbase page:

kdesvn-build is a tool to allow users and developers to easily download and build the latest versions of the KDE Software Compilation (KDE SC) from the KDE source code repositories. It automates the following tasks and more:

• Performing the initial checkout.
• Handling updates for modules that are already checked out.
• Setting up the build system for the module.
• Performing the build and install.
• Specifying your CMake options or configure flags (so you don’t have to remember them every time).

It’s basically a script that does the hard work for you. And it’s pretty, too.

kdesvn-build in action

Since I want to keep my stable KDE SC version, I have a special user called kde-devel to run trunk. Everything will be install in this user’s home directory – no root access is needed, and if something breaks, the risk is minimal that it’ll affect my whole system.

You can do the same with your usual user and some scripts, see Increased Productivity in KDE4 with Scripts for more information.

1. Create and setup user

First this kde-devel user has to be created:

useradd -m -G [groups] -s /bin/bash kde-devel

[groups] depends on how much rights you want to give this user, for example the right to access sound or use sudo. For my kde-devel I used

useradd -m -G users,audio,optical,storage,video -s /bin/bash kde-devel

Now, add a password:

passwd kde-devel

To use applications from trunk instead of the stable version installed, you have to set the correct environmental variables. I added the code from this example .bashrc to /home/kde-devel/.bashrc and changed the line

export QTDIR=$HOME/qt-kde

to

export QTDIR=$HOME/qt4

since that’s where qt-copy will be installed.

2. Install required packages

I’m an Arch Linux user and used the command here to install the required packages. You can find similar information for your distribution on this page.

Regarding Qt,  .kdesvn-buildrc (more about this configuration file later) states:

# KDE /trunk requires a very recent Qt so qt-copy is the best route if you're
# building /trunk.  If you are building an older branch you may use your
# system installed Qt by setting qtdir to point to it (what qmake -v
# reports with the /lib removed).

So, I chose to let kdesvn-build compile qt-copy as well.

3. Get and setup kdesvn-build

At the time of writing, the latest version of kdesvn-build is 1.11. If you want to use the commands below, substitute <version> with your version number, e.g. 1.11.

I downloaded kdesvn-build as kde-devel and extracted the tar to ~/kdesvn/kdesvn-build (you may choose a different location if you want):

su - kde-devel
<write password for kde-devel>
mkdir -p ~/kdesvn/kdesvn-build
wget http://kdesvn-build.kde.org/releases/kdesvn-build-<version>.tar.bz2
tar xjvf kdesvn-build-<version>.tar.bz2 -C ~/kdesvn/kdesvn-build/

Before using kdesvn-build it needs to be configured. There’s a sample configuration file in the extracted directory – all we have to do is to copy it to ~/.kdesvn-buildrc and edit it to fit our needs.

cp ~/kdesvn/kdesvn-build/kdesvn-build-<version>/kdesvn-buildrc-sample ~/.kdesvn-buildrc
<your favorite editor> ~/.kdesvn-buildrc

The file is quite long, but don’t worry, most of the text consists of comments. I found the default configuration to be good for my purposes, the only thing I did was to comment out some modules that I didn’t want, for example

#module kdetoys
#end module

By default KDE trunk and Qt will be installed at ~/kde and ~/qt4, respectively.

4. Build

When everything has been set up we can let kdesvn-build perform its magic. As kde-devel:

~/kdesvn/kdesvn-build/kdesvn-build-<version>/kdesvn-build

Be patient, this will take a while. I encountered some problems during the build – see the next section for solutions. Remember that you can cancel the build with Ctrl-C.

kdesvn-build also offers some useful options, use --help to list them all.

~/kdesvn/kdesvn-build/kdesvn-build-<version>/kdesvn-build --help

5. Troubleshooting

As said, the process wasn’t flawless for me – actually, I ran into a problem very early. If you use the same version of kdesvn-build, it’s likely you’ll encounter this as well.

Can’t checkout qt-copy

Error updating qt-copy, removing from list of packages to build.
> Can't checkout qt-copy: No such file or directory at /home/kde-devel/.bin/kdesvn-build line 1981.

The problem is known, but I’m not sure if I can say the same about the cause. If you look in the logs you’ll see

less ~/kdesvn/log/latest/qt-copy/error.log

# kdesvn-build running: 'git' 'clone' '--' 'git://gitorious.org/+kde-developers/qt/kde-qt.git' '/home/kde-devel/kdesvn/qt-copy'
Initialized empty Git repository in /home/kde-devel/kdesvn/qt-copy/.git/
fatal: The remote end hung up unexpectedly
fatal: early EOF
fatal: index-pack failed

To solve it I cloned the git repository manually by copy-pasting the command from the log:

'git' 'clone' '--' 'git://gitorious.org/+kde-developers/qt/kde-qt.git' '/home/kde-devel/kdesvn/qt-copy'

Here kdesvn-build has no problem to update and build qt-copy after this fix.

Phonon-related problems

Apparently kdebase needs Phonon from kdesupport now, which also is the default option in the new kdesvn-buildrc-sample file. My problems with Phonon vanished after upgrading to kdesvn-build 1.11 and making a new .kdesvn-buildrc based on the new sample file.

file INSTALL cannot copy file

CMake Error at workspace/plasma/generic/scriptengines/python/cmake_install.cmake:76 (FILE):
file INSTALL cannot copy file
"/home/kde-devel/kdesvn/kdebase/workspace/plasma/generic/scriptengines/python/plasmascript.py"
to "/usr/lib/python2.6/site-packages/PyKDE4/plasmascript.py".
Call Stack (most recent call first):
workspace/plasma/generic/scriptengines/cmake_install.cmake:39 (INCLUDE)
workspace/plasma/generic/cmake_install.cmake:42 (INCLUDE)
workspace/plasma/cmake_install.cmake:38 (INCLUDE)
workspace/cmake_install.cmake:90 (INCLUDE)
cmake_install.cmake:39 (INCLUDE)

The first time I ran kdesvn-build, kdebase failed to compile due to this error. A quick search pointed me to this Techbase page, which says

try to set: -DPYTHON_SITE_PACKAGES_DIR=~/.local/lib/python2.6/site-packages (check that this path corresponds to something in your system, you might have a different version of python) as a parameter for cmake (or cmakekde)

I had no idea how to do that, so I asked on IRC and was suggested to run cmake . -DPYTHON_SITE_PACKAGES_DIR=[...] in the kdebase build directory:

cd ~/kdesvn/build/kdebase
cmake . -DPYTHON_SITE_PACKAGES_DIR=~/.local/lib/python2.6/site-packages
make
make install

Other problems

I didn’t run into any other problems, but if you do, I recommend that you check out Troubleshooting on Techbase and see if you find a solution. Sometimes some modules simply won’t compile, with a higher risk on Mondays. Visit Dashboard to see the build status.

6. Run

Now finally for the fun part – trying out new features in trunk. You can find more information about this topic on this page.

Launch applications

Sometimes I want to launch the trunk version of individual applications from my stable KDE SC session, for example if I want to see if I can reproduce a bug. To handle things like the DISPLAY variable I use sux, which is available in many distribution repositories. (If you’re an Arch user like me, you can get it from AUR).

For example, to run Dolphin:

sux - kde-devel
<write kde-devel password>
dolphin

As simple as that. The - after sux is very important – it ensures that the environmental variables we set in /home/kde-devel/.bashrc are used.

Start a new session

You can also start a full KDE trunk session, but first you need to tell your login manager how to start it. For KDM this is done by adding a desktop file to `kde4-config --prefix`/share/apps/kdm/sessions/.

We want to add it to our stable version of KDM, so make sure to use another user than kde-devel for the following commands (you’ll need root privileges):

cd `kde4-config --prefix`/share/apps/kdm/sessions/ # use kde-config if you're on KDE SC 3.x
cp kde.desktop kdetrunk.desktop
<your favorite editor> kdetrunk.desktop

Change the lines (yours might differ slightly)

Exec=/usr/bin/startkde
TryExec=/usr/bin/startkde

to where you’ve installed trunk, in my case

Exec=/home/kde-devel/kde/bin/startkde
TryExec=/home/kde-devel/kde/bin/startkde

and Name=KDE to something else, for example Name=KDE trunk.

That’s it. Now you can start a new session (Leave -> Switch User from the default application launcher), choose “KDE trunk” and login with your kde-devel user. To switch between sessions, you can use Ctrl-Alt-Fx, usually Ctrl-Alt-F7 and Ctrl-Alt-F8.

It’s also possible to run a nested session, see Techbase for more information.

Tips

I hope this has helped some to build KDE SC from SVN, and I look forward to hearing your feedback. Before I go back and play around in trunk, I’ll share some tips with you.

Make it easier to run kdesvn-build

By adding kdesvn-build to your PATH, you can run the script by simply typing kdesvn-build. I do this by making a symlink in ~/.bin and adding that directory to PATH:

su - kde-devel
mkdir -p .bin
ln -s kdesvn/kdesvn-build/kdesvn-build-<version>/kdesvn-build .bin/

and add the line

PATH=$PATH:$HOME/.bin

to ~/.bash_profile. Next time you login you can simply use the command kdesvn-build.

Make it even easier to run kdesvn-build

If you like to update often, you can add kdesvn-build to your regular user’s application launcher.

1. Run kmenuedit
2. Navigate to where you want to put kdesvn-build
3. Click on New Item in the toolbar and name it kdesvn-build
4. Click on the icon to choose a nice icon for the menu item
5. Enter <path to kdesvn-build> in Command, for example /home/kde-devel/kdesvn/kdesvn-build/kdesvn-build-<version>/kdesvn-build
6. Click on Advanced and check Run in terminal and Run as different user
7. Write kde-devel as username and click on Save in the toolbar

If you use Konsole as your terminal you can add --noclose in Terminal options to make it stay open after the build is finished.

Check logs for errors

If a module failed to build, it’s often a good idea to check the logs to see what went wrong. By default kdesvn-build stores them at ~/kdesvn/log. I’ve found it useful to make a symlink to the latest logs in the home direcory of kde-devel:

ln -s ~/kdesvn/log/latest/ ~/log

Pause kdesvn-build

So kdesvn-build is halfway through compiling kdebase when you realize you want to watch a HD movie – what to do? No worries, you can easily pause the script (this won’t work if you use the tip from “Make it even easier to run kdesvn-build”).

To pause the script, press Ctrl-Z. You’ll see something like

[1]+  Stopped                 kdesvn-build

The number within the brackets is the job number, in this example 1. To resume it, run

fg 1

where fg stands for foreground and 1 is the job number.