Developer – Finding assistance

Docs: Where to find the development team

Mon, 01 Jan 0001 00:00:00 +0000

The KDE developers are here to assist you if you need any help with KDE software development.

There are several ways to get in touch with KDE developers, either generally or for a specific project. The most important communication channels are:

Real-time chat: #kde-devel:kde.org room on Matrix (all KDE rooms are listed here)
Forum: Development forum on KDE Discuss
Mailing list: kde-devel (Learn more about mailing lists)

These are general KDE development communication channels, and you may be directed to a more appropriate place for the project you're interested in.

Many projects and teams have their own real-time chat channels, which can be found on the Matrix Rooms page. If your Matrix client supports browsing spaces (like Element) then you can join the KDE Community Matrix Space. It will display the same list of rooms as you see below, but easily accessible inside of your client.
There is a list of mailing lists if you want to find a mailing list for a specific team directly.

The Get Involved wiki page includes links to more general contribution teams.

Docs: Learning more

Mon, 01 Jan 0001 00:00:00 +0000

Most KDE software is written in C++ using the Qt toolkit and KDE Frameworks. Though prior experience with these technologies or other programming languages is helpful, you don't need to be a C++ programmer to get started! For example, no programming knowledge whatsoever is required to do things like improving text labels.

If you'd like to dive deeper into it:

The Qt wiki contains a list of online books for learning Qt programming.
Qt also provides lots of examples you can look at.
For visual learners, this YouTube playlist of QML tutorials by KDE patron KDAB may be useful.
The reference API documentation for KDE Frameworks can be found on the KDE API website.
KDE also provides a curated wiki page full of learning resources.

Docs: Choose what to work on

Mon, 01 Jan 0001 00:00:00 +0000

The best place to start is with something that personally affects you: for example, a small bug or glitch in a piece of KDE software that you use, or an idea you have for a new feature.

The personal angle will impart more motivation to get started, push through challenges, and finish your contribution to KDE. This isn't a requirement, but it's a strong indicator that you'll be able to complete the task as a brand new KDE contributor.

If everything works great for you, here are some other ideas for starting points:

Improve awkwardly-worded messages and labels that are written in English. This is a great way for non-programmers to contribute! If you can compile software and have a good grasp of English, you can make a big difference here.
Work on Junior Jobs, which are small tasks that are suitable for beginners (both bugs and features). You can find them available both on Bugzilla and Gitlab.
Work on bugs related to KDE's Usability & Productivity initiative, many of which are small and easy.
Work on 15 minute bugs, bugs that can be found within 15 minutes of using Plasma.

There are many other lists of issues you can take a look at:

The Usability and Productivity goal wiki page mentioned before has its own list of easy bugs you can tackle.
The Bug Triaging team has many search queries that can be useful to search for bugs.
The Gardening team has a stale merge requests list full of old merge requests with interesting but unfinished ideas. You can ask their developers if it's okay to take over the work from them.
The list of app ideas is a good entrypoint if you are looking to make a new KDE application from scratch.

Try not to start out by proposing or working on major features or significant design changes. These can be controversial, and the smoothest way to get going is by working on relatively non-controversial bugfixes. Start slowly and build trust!

Once you've got a general idea about what you want to work on, you can get in touch with the existing developers and they can help you out by pointing you to the right place in the code and providing advice about how to tackle the problem.

Docs: Source code cross-referencing

Mon, 01 Jan 0001 00:00:00 +0000

To search for a class, method, signal name or any other sort of code in all KDE repos, including QML and CMake, KDE provides a code referencing tool to index code in the various KDE repositories: the KDE Source Code Cross Reference (LXR) website.

By clicking on the Branch group menu at the top right, you can select whether you'd like to see KDE software in Qt5 or Qt6, and whether to search for code in the master branches or from the stable (released) branches.

LXR has two search modes:

On the "Identifier" search page, you can search for:

Class names, for example RenameDialog, StatJob, QLatin1String, or QListWidget.
Method names, for example addConfigSources, setAboutData, or deleteLater.
Signal names, for example mimeTypeFound or errorOccurred.

The LXR identifier search.

On the "General search" page you can search for strings:

For example, if you'd like to find in which source file the string "Paste Clipboard Contents" from Dolphin's context menu is defined, type "Paste Clipboard Contents" in the Or containing: field. This search includes class, method, and signal names.

The LXR general search.

Other ways to search across all of the KDE git repositories:

By using KDE's Gitlab instance: pressing / or clicking on the search bar from the home page will trigger a global search. You can also visit a specific project's repository and use the same mechanism to search in the project's code.
By using a local checkout of several repositories with kde-builder: kde-builder --src-only will download the source code of more than 300 KDE git repositories in ~/kde/src. You can then search inside this directory using any tool, like grep "search query" --recursive --ignore-case.

Docs: Installing build dependencies

Mon, 01 Jan 0001 00:00:00 +0000

This page handles the normal issues related to missing dependencies when building with kde-builder. If you have any specific issues, consult our Troubleshooting page or contact the developers.

⚠️ Before proceeding

Make sure you have followed Set up kde-builder in full and have installed the default package dependencies:

kde-builder --install-distro-packages

How to install all the build dependencies of one package

Often the simplest solution to the problem of missing dependencies is to automatically install all of the project's required dependencies.

Because most distributions keep track of package dependencies, most also provide their own built-in commands to install all the build dependencies of a package.

While these commands will not always install all dependencies you will need when compiling KDE software (for example, when compiling with kde-builder, where the software is always changing), they will make your dependency resolution faster.

Debian, Ubuntu, Kubuntu, and KDE neon

Make sure that you have enabled the source repositories for your distribution, as explained in Debian/Ubuntu-based distributions. Without them, apt build-dep will fail with E: You must put some 'deb-src' URIs in your sources.list.

All known build dependencies for the package you want to build can be installed with apt build-dep:

sudo apt build-dep dolphin

openSUSE

All known build dependencies for the package you want to build can be installed with zypper source-install --build-deps-only:

sudo zypper --plus-content repo-source source-install --build-deps-only dolphin

The --plus-content option is required to temporarily enable the source repositories containing the build dependency information.

Fedora

All known build dependencies for the package you want to build can be installed with dnf builddep:

sudo dnf builddep dolphin

Using build errors to find missing dependencies

Whenever you attempt to compile a project and it fails to build, most of the time this is caused by a missing dependency.

Let's say you see the following error when compiling a project:

-- Could NOT find KF6TextWidgets (missing: KF6TextWidgets_DIR)
-- Could NOT find KF6TextWidgets: found neither KF6TextWidgetsConfig.cmake nor kf6textwidgets-config.cmake
CMake Error at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
 Could NOT find KF6 (missing: TextWidgets)

This error is provided by CMake and it means you are missing the KDE Frameworks 6 library KTextWidgets.

For projects using Meson, the error message would look like this:

Build-time dependency gi-docgen found: NO (tried pkgconfig and cmake)

docs/api/meson.build:5:15: ERROR: Dependency "gi-docgen" not found, tried pkgconfig and cmake

Meson projects typically prefer using pkgconfig over CMake package configuration files.

The error here states that Meson could not find the pkgconfig file for gi-docgen (most likely a file with the extension .pc) or the CMake file (most likely a file with the extension .cmake) that contains gi-docgen in its name (case insensitively).

Generic search

There are two types of dependencies: build dependencies and runtime dependencies. The distribution package names for build dependencies usually begin with lib and/or end in -dev or -devel, whereas runtime dependencies usually just start with lib.

For build dependencies you will likely only need packages that end in -dev or -devel, but in some cases you might need to install packages starting with lib too.

In the previous cmake example, KTextWidgets is a build dependency.

The main way to find the package that provides KTextWidgets is to search for it in your package manager:

Debian and derivatives: sudo apt search textwidgets
openSUSE: sudo zypper search textwidgets
Fedora: sudo dnf search textwidgets
Arch: sudo pacman -Ss textwidgets
FreeBSD: sudo pkg search textwidgets

Just searching for the component usually reveals the right package name, although it ultimately amounts to guessing or trial-and-error. KDE frameworks or other libraries often have various, slightly different, names, depending on the context. For example, KTextWidgets might sometimes be called TextWidgets, KF6TextWidgets or similar names. If you can't find anything for one name, try searching for such variations.

The usual pattern you will find for dependency packages looks like this:

Debian and derivatives: lib<packagename>-dev or <packagename>-dev
openSUSE and Fedora: kf6-<packagename>-devel or libKF6<PackageName>
Arch: <packagename>

Tip

You can also use web shortcuts provided by KRunner, which will open the package search website for each distribution.

For example: open KRunner with Alt + Space, then type: debian: textwidgets. Your browser will open the "textwidgets" page of the Debian Package Search website automatically.

Finding specific packages using CMake package configuration files

A more efficient way is to use the functionality provided by your package manager to search for the CMake config file:

Debian and derivatives: apt-file find KF6TextWidgetsConfig.cmake
openSUSE: zypper what-provides 'cmake(KF6TextWidgets)'
Fedora: dnf provides 'cmake(KF6TextWidgets)'
Arch: pkgfile KF6TextWidgetsConfig.cmake

Fedora and openSUSE come with this functionality by default. On Debian, you will need to install apt-file manually. On Arch, install pkgfile.

If while using apt-file you get an error similar to the following:

The imported target "Qt6::qtwaylandscanner" references the file
 "/usr/lib/qt6/libexec/qtwaylandscanner"
but this file does not exist.

You can run this to see what package contains this file:

apt-file find /usr/lib/qt6/libexec/qtwaylandscanner

You will get the following output:

qt6-wayland-dev-tools: /usr/lib/qt6/libexec/qtwaylandscanner

So the package you need to install is qt6-wayland-dev-tools.

Finding specific packages using pkgconfig files

Similarly to the above, some distributions also allow querying for packages using pkgconfig files:

openSUSE: zypper what-provides 'pkgconfig(gi-docgen)'
Fedora: dnf provides 'pkgconfig(gi-docgen)'

Finding missing executables

If the CMake error looks like the following:

CMake Error at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
 Could NOT find Sass (missing: Sass_EXECUTABLE)
Call Stack (most recent call first):
 /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:600 (_FPHSA_FAILURE_MESSAGE)
 cmake/modules/FindSass.cmake:48 (find_package_handle_standard_args)
 CMakeLists.txt:31 (find_package)

This is due to CMake not finding the executable named sass (most likely a file /usr/bin/sass).

To solve this, you can specifically search for the executable in distribution packages:

Debian and derivatives: apt-file search /usr/bin/sass
Fedora: sudo dnf provides sass
openSUSE: sudo zypper search --provides /usr/bin/sass
Arch: sudo pacman -F /usr/bin/sass
FreeBSD: sudo pkg provides sass

Configuring pkg-provides on FreeBSD

Click here to set up pkg-provides on FreeBSD

Once you run pkg provides, if you face the error:

makeinfo: not found WARNING: 'makeinfo' is missing on your system.

This means you are missing the provides plugin:

sudo pkg install pkg-provides

Uncomment the following lines in /usr/local/etc/pkg.conf and add provides to the supported plugin list:

PKG_PLUGINS_DIR = "/usr/local/lib/pkg/";
PKG_ENABLE_PLUGINS = true;
PLUGINS [ provides ];

To confirm it is working:

sudo pkg plugins
# NAME DESC VERSION
# provides A plugin for querying which package provides a particular file 0.7.3
sudo pkg provides -u
sudo pkg provides bin/makeinfo
# Name : texinfo-7.0.3,1
# Comment : Typeset documentation system with multiple format output
# Repo : FreeBSD
# Filename: usr/local/bin/makeinfo
sudo pkg install texinfo