Advanced features

Partially building a module

It is possible to build only pieces from a single KDE module. For example, you may want to compile only one program from a module. kdesrc-build has features to make this easy. There are several complementing ways to do this.

Checking out portions of a module

This is perhaps the best way to do this. When it works, it will save you download time and disk space. What happens is that kdesrc-build will download only the parts of a module that you specify. This is done using the checkout-only option for a module, which will specify a list of directories to download.

Tip

If you do not already know what to download from a module, it may be a good idea to browse the Subversion layout for a module first, using WebSVN.

To only grab KUser and KSystemLog from kdeadmin, you could use checkout-only like this:

module kdeadmin
  checkout-only kuser ksystemlog
end module

Important

The directories will be built in the order they are listed in the option. If one of the directories needs something else from the module to compile, then you need to make sure they are both in the checkout-only line, and that the required dependency goes before the directory that needs it.

Also, sometimes an application may need other directories and it is hard to figure out what they are, which may require some trial and error of constantly adding directories to the option to figure out. This option depends on support from the build system of the module, so it is only useful for modules that are collections of individual applications.

One final note to make about this option: If you change the value of this option, you should use kdesrc-build --refresh-build module in order to ensure that the module is reconfigured properly. In addition, kdesrc-build will never remove existing files if you take away the number of directories from your checkout-only option, or add the option to a module that has already been checked out.

Removing directories from a build

Instead of restricting what is downloaded, it is possible to download everything but have the build system leave out a few directories when it does the build. This may be useful if one directory always breaks and is unnecessary to the rest of the module.

This is controlled with the do-not-compile option. It works similar to the checkout-only option just described, in that it is simply a list of directories that should not be compiled.

Important

Also like checkout-only, this option requires at least that the build system for the module is reconfigured after changing it. This is done using the kdesrc-build --reconfigure module command.

To remove the python directory from the kdebindings build process:

module kdebindings
  do-not-compile python
end module

Note

This function depends on some standard conventions used in most KDE modules. Therefore it may not work for all programs.

Branching and tagging support for kdesrc-build

What are branches and tags?

Subversion supports managing the history of the KDE source code. KDE uses this support to create branches for development, and to tag the repository every so often with a new version release.

For example, the KMail developers may be working on a new feature in a different branch in order to avoid breaking the version being used by most developers. This branch has development ongoing inside it, even while the main branch (called /trunk) may have development going on inside of it.

A tag, on the other hand, is a snapshot of the source code repository at a position in time. This is used by the KDE administration team to mark off a version of code suitable for release and still allow the developers to work on the code.

In Subversion, there is no difference between branches, tags, or trunk within the code. It is only a convention used by the developers. This makes it difficult to properly support branches and tags within kdesrc-build. However, there are some things that can be done.

How to use branches and tags

Support for branches and tags is handled by a set of options, which range from a generic request for a version, to a specific URL to download for advanced users.

The easiest method is to use the branch and tag options. You simply use the option along with the name of the desired branch or tag for a module, and kdesrc-build will try to determine the appropriate location within the KDE repository to download from. For most KDE modules this works very well.

To download kdelibs from KDE 4.6 (which is simply known as the 4.6 branch):

module kdelibs
  branch 4.6
  # other options...
end module

Or, to download kdemultimedia as it was released with KDE 4.6.1:

module kdemultimedia
  tag 4.6.1
  # other options...
end module

Tip

You can specify a global branch value. But if you do so, do not forget to specify a different branch for modules that should not use the global branch!

Advanced branch support options

kdesrc-build supports two options for situations where branch and tag guess the correct path improperly: module-base-path and override-url.

  • module-base-path is used to help kdesrc-build fill in the missing part of a module's path. In the KDE repository, all of the paths are of the form svnRoot/module-base-path/module-name. Normally kdesrc-build can figure out the appropriate middle part by itself. When it cannot, you can use module-base-path, like this:

    module kdesupport
        # kdesupport supports various tags to easily organize the required
        # software for a given KDE Platform release.
        module-base-path tags/kdesupport-for-4.5
    end module
    

    This would cause kdesrc-build to download kdesupport from (in this example), svn://anonsvn.kde.org/home/kde/tags/kdesupport-for-4.5.

    Tip

    In previous versions of kdesrc-build, the module-base-path was handled differently. If you encounter trouble using an old module-base-path definition perhaps you should verify that the actual path is as kdesrc-build expects by using the --pretend option.

  • The override-url option, on the other hand, requires you to specify the exact path to download from. However, this allows you to pull from paths that previous versions of kdesrc-build would have no hope of downloading from. Currently, the module-base-path option should be sufficient for any Subversion source URL.

    Important

    kdesrc-build will not touch or correct the value you specify for override-url at all, so if you change your svn-server setting, you may need to update this as well.

How kdesrc-build tries to ensure a successful build

Automatic rebuilds

kdesrc-build used to include features to automatically attempt to rebuild the module after a failure (as sometimes this re-attempt would work, due to bugs in the build system at that time). Thanks to switching to CMake the build system no longer suffers from these bugs, and so kdesrc-build will not try to build a module more than once. There are situations where kdesrc-build will automatically take action though:

  • If you change configure-flags or cmake-options for a module, then kdesrc-build will detect that and automatically re-run configure or cmake for that module.

  • If the buildsystem does not exist (even if kdesrc-build did not delete it) then kdesrc-build will automatically re-create it. This is useful to allow for performing a full --refresh-build for a specific module without having that performed on other modules.

Manually rebuilding a module

If you make a change to a module's option settings, or the module's source code changes in a way kdesrc-build does not recognize, you may need to manually rebuild the module.

You can do this by simply running kdesrc-build --refresh-build module.

If you would like to have kdesrc-build automatically rebuild the module during the next normal build update instead, you can create a special file. Every module has a build directory. If you create a file called .refresh-me in the build directory for a module, kdesrc-build will rebuild the module next time the build process occurs, even if it would normally perform the faster incremental build.

Tip

By default, the build directory is ~/kdesrc/build/module/. If you change the setting of the build-dir option, then use that instead of ~/kdesrc/build.

Rebuild using .refresh-me for module kdelibs:

% touch ~/kdesrc/build/kdelibs/.refresh-me
% kdesrc-build

Changing environment variable settings

Normally kdesrc-build uses the environment that is present when starting up when running programs to perform updates and builds. This is useful for when you are running kdesrc-build from the command line.

However, you may want to change the setting for environment variables that kdesrc-build does not provide an option for directly. (For instance, to setup any required environment variables when running kdesrc-build on a timer such as Cron) This is possible with the set-env option.

Unlike most options, it can be set more than once, and it accepts two entries, separated by a space. The first one is the name of the environment variable to set, and the remainder of the line is the value.

Set DISTRO=BSD for all modules:

global
  set-env DISTRO BSD
end global

Resuming builds

Resuming a failed or canceled build

You can tell kdesrc-build to start building from a different module than it normally would. This can be useful when a set of modules failed, or if you canceled a build run in the middle. You can control this using the --resume-from option and the --resume-after option.

Note

Older versions of kdesrc-build would skip the source update when resuming a build. This is no longer done by default, but you can always use the --no-src command line option to skip the source update.

Resuming the build starting from kdebase:

% kdesrc-build --resume-from=kdebase

Resuming the build starting after kdebase (in case you manually fixed the issue and installed the module yourself):

% kdesrc-build --resume-after=kdebase

Ignoring modules in a build

Similar to the way you can resume the build from a module, you can instead choose to update and build everything normally, but ignore a set of modules.

You can do this using the --ignore-modules option. This option tells kdesrc-build to ignore all the modules on the command line when performing the update and build.

Ignoring extragear/multimedia and kdereview during a full run:

% kdesrc-build --ignore-modules extragear/multimedia kdereview

Changing options from the command line

Changing global options

You can change the setting of options read from the configuration file directly from the command line. This change will override the configuration file setting, but is only temporary. It only takes effect as long as it is still present on the command line.

kdesrc-build allows you to change options named like option-name by passing an argument on the command line in the form --option-name=value. kdesrc-build will recognize whether it does not know what the option is, and search for the name in its list of option names. If it does not recognize the name, it will warn you, otherwise it will remember the value you set it to and override any setting from the configuration file.

Setting the source-dir option to /dev/null for testing:

% kdesrc-build --pretend --source-dir=/dev/null

Changing module options

It is also possible to change options only for a specific module. The syntax is similar: --module,option-name=value.

This change overrides any duplicate setting for the module found in the configuration file, and applies only while the option is passed on the command line.

Using a different build directory for the kdeedu module:

% kdesrc-build --kdeedu,build-dir=temp-build