Building KDE 4 using the kdesrc-build tool

Introduction to kdesrc-build

kdesrc-build (formerly 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).
Logging build errors so you can review them easier for troubleshooting.

It is not the end-all for your troubles building KDE, Troubleshooting still applies. Many errors that occur using other methods occur here too, you read the log files that are stored for you.

Why use kdesrc-build?

So why use kdesrc-build? There are several reasons you may like to use it:

Less manual editing of commands. Instead of having to remember to add the correct options to the cmake command line or configure command, you can setup the options once and then kdesrc-build will use your settings from then on, saving you from wasting time because you forgot to enable a setting.
Command logging to help debug build failures. kdesrc-build logs all command outputs to a file. This has several advantages:
1. When a module fails to build, you already have the error output saved to disk, ready to be viewed and compared with other error messages to aid debugging.
2. Quieter output. Even with CMake, the output of Qt or a KDE SC module build can be extensive. kdesrc-build does not show the details of a module build (but will show the progress), instead an overview of the build process is displayed.
It's just easier. Instead of having to learn how to use the Subversion and git tools, and how to setup a KDE build system, you can specify what modules you want build, where to install them to, and any other options you want and then have kdesrc-build actually do it, even while you're away from the computer or busy doing other things.
It's easy to step in yourself. kdesrc-build uses a standard source and build directory layout, and calls the same commands you would. So kdesrc-build will not interfere with you performing the build or editing the source yourself if you so choose.

Setting up

Prerequisites

kdesrc-build is fairly easy to install and setup, but you also need to have the right software installed to build KDE. The requirements to build KDE are available as follows:

KDE 4: KDE 4 Requirements

kdesrc-build requires Perl 5.10 or higher. It is installed by default with most distributions, and is included in the link above. Check your version of Perl with:

perl -v

You will also need libwww (sometimes called LWP), a collection of Perl Internet-related modules, and XML::Parser to support the XML-based KDE Project database. Both of these modules are extremely common and should be available in your distribution's packager manager. For example for SUSE install them with

yast -i perl-libwww-perl

kdesrc-build itself may be packaged on your distribution, which allows you to easily install its dependencies as well. (Debian provides packages and a Fedora package is pending a fix to the kdesrc-build sources).

Note
kdesrc-build is developed on a Linux system, but it should work on the various BSD distributions as well (although GNU tools may be required).

Download and install kdesrc-build

Download kdesrc from git like this:

git clone git://anongit.kde.org/kdesrc-build.git ~/kdesrc

Setup the configuration

Now you should setup your configuration. For the most part the defaults in the included kdesrc-buildrc-sample should be sufficient.

cp ~/kdesrc/kdesrc-buildrc-sample ~/.kdesrc-buildrc

Now you can start kdesrc-build using the commands

cd
./kdesrc/kdesrc-build

Now you can edit the configuration file ~/.kdesrc-buildrc

Tip
Note that the config file's name begins with a leading ., making it a hidden file. You may need to show hidden files in Dolphin or Konqueror to find the configuration file to edit it. Or, you can edit the sample before copying it to ~/.kdesrc-buildrc.

Also, make sure that the modules you'll want to build are included. You'll want the following at the least:

qt-copy, kdesupport, kdelibs, kdepimlibs, kdebase

Modules are built in the order they appear in your ~/.kdesrc-buildrc, so the first module should be qt-copy, kdelibs should be before any other KDE SC module, and so on.

Note
The sample configuration file does include these modules by default, you won't need to make many changes unless you'd like to add some modules to the build by uncommenting them.

You may want to enable the make-install-prefix option if you are installing KDE SC or Qt to a directory that is not in your home directory. make-install-prefix allows you to run su or sudo during the make install process so you can install files as root, or set certain programs to execute with higher permissions (This is required for certain programs to execute properly).

module kdelibs
  make-install-prefix sudo -S # sudo with no stdin
end module

module kdebase
  make-install-prefix sudo -S
end module

If a module you'd like to build isn't already present, simply add

module <module-name>
end module

at the end of the ~/.kdesrc-buildrc. <module-name> would be whatever the module is called in the software repository (for instance, kdemultimedia).

Git-based modules

Some KDE projects use the "git" source-control software instead of Subversion (as part of an ongoing migration to git). This includes software like Amarok and Konversation.

To build these modules in kdesrc-build, you just need to add a couple of lines to the module configuration. For example, konversation is developed in the Git repository at [1]. So you would just add a module (you can pick whatever name for the module you like, as long as it's not already used):

module konversation
    repository git://anongit.kde.org/konversation
    branch master
end module

In this case I selected the "master" branch since that is the default git branch.

Now whenever you build konversation, kdesrc-build will use git instead of Subversion.

Useful kdesrc-build commands

kdesrc-build is driven from the command line, so here's a guide to some of the more useful command line options:

Option	Effect
`--pretend` (Short form `-p`)	This option is like a dry run. kdesrc-build will process the options and its configuration like normal, and run through the build as normal, but instead of downloading or running the build will instead output what kdesrc-build would have done. You should always run with -p before running kdesrc-build to make sure it is doing what you expect.
`--no-svn` (Alt. form `--no-src`)	This option skips the source code update step. This is useful if you're running kdesrc-build again soon after the last update and don't want to wait to find out there were no changes.
`--refresh-build`	This option causes kdesrc-build to delete the current build information for the given modules and start building them again from scratch. This option takes a lot of time but gives the best chance of a successful build.

Any other non-option arguments on the command line are assumed to be modules to build (and are built in the order provided on the command line). If no modules are specified, all of the modules listed in the ~/.kdesrc-buildrc are built in the order listed in the file.

Build

We're almost there. If you're happy with your settings then it's time to test out kdesrc-build. In theory things are as simple as running kdesrc-build and then coming back later. ;)

cd ~/kdesrc
./kdesrc-build

You may want to test by building qt-copy first however.

cd ~/kdesrc
./kdesrc-build qt-copy

Tip
If you have the GNU screen program available then you should definitely use it to run kdesrc-build, as you can detach your kdesrc-build session and logout while kdesrc-build is still running.

If the build failed (kdesrc-build will error out with a nice bright red error message) then there are several possibilities:

You are missing a key piece of required software (such as a development library)
The KDE SC code being compiled is broken in some fashion to where it won't build. This is commonly due to newly committed code that worked on the developer's machine, or occasionally on Mondays (when incompatible changes are permitted to kdelibs).
kdesrc-build is not setup properly. You may be trying to install to a directory that you have no permissions to access for instance, or you may have specified a system qtdir that does not exist.
The module may depend on a newer version of qt-copy or kdelibs (or other module). In this case you'll have to run kdesrc-build to update the out-of-date module first.

How do you find out what the error was? The output of the failing command will be in the log directory. By default, all log output is in the log subdirectory of the KDE SC source directory. The log directory is laid out like this: log/date-run/module/output-file.log. To simplify finding the appropriate file, there are a couple of symlinks created:

log/latest always has the debugging output for the last time kdesrc-build was run (--pretend doesn't count toward this) log/latest/<module>/error.log has the debugging output for the command that caused a module build to fail.

For instance if qt-copy just failed to build you could read the output like this:

cd ~/kderc
kwrite log/latest/qt-copy/error.log

Replace kwrite with your preferred editor. Hopefully the output can guide you to resolving the problem. For instance, if the failure is a cmake output saying you're missing a library, install that library and try again. ;) For link errors you can try running a --refresh-build on the module (or if that doesn't work, required libraries like qt-copy and kdelibs).

If you're stumped by the error you may want to wait a day and try updating again, and hope that the reason for the error has been fixed. You can also try mailing the kde-devel mailing list to see if others know about the problem or have had similar issues.

Running KDE

Assuming you got enough of the modules to build and install to have a working KDE installation, you'll still need to setup your environment correctly to run it. kdesrc-build doesn't help you out here (yet), so you should follow the instructions here.

Make sure to use the same paths as the ones you defined in .kdesrc-buildrc: for the KDEDIRS and KDEDIR variable use the setting of the "prefix" option (in the global section). For the QTDIR variable use the setting of the "qtdir" option.

Keeping KDE up to date

Keeping your KDE installation up to date is as simple as running kdesrc-build again. Every kdesrc-build has these phases:

Update the source code for all modules being built.
Build and then install all the modules.

Old build directories are not deleted by default, so the build after a small update will not normally take as long as the initial build of a module. This is called "incremental make". However it may be necessary at times to perform a full rebuild due to inconsistencies between the build directory configuation and changes to the source directory. You can use the --refresh-build option to force a full rebuild.

For more information on how to take advantage of kdesrc-build, see the online documentation for kdesrc-build, which describes all of the module options and command line options available for kdesrc-build and gives tips on how to perform various useful tasks.

If you have any questions that are not answered please feel free to add them under the Discussion entry for this page and hopefully someone will be able to get the answer.

Getting Started/Build/kdesrc-build

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