From a terminal window, log in to the user you are using to compile KDE software and execute the script:

    % kdesrc-build --metadata-only

This command will setup the source directory and connect to the KDE Git repositories to download the database of KDE git repositories, and the database of dependency metadata, without making any further changes. It is useful to run this separately as this metadata is useful for other kdesrc-build commands.

With the project metadata installed, it is possible to preview what kdesrc-build will do when launched. This can be done with the --pretend command line option.

    % ./kdesrc-build --pretend

You should see a message saying that some packages were successfully built (although nothing was actually built). If there were no significant problems shown, you can proceed to actually running the script.

    % kdesrc-build --stop-on-failure

This command will download the appropriate source code, and build and install each module in order, but will stop if a module fails to build (due to the --stop-on-failure option). Afterwards, you should see output similar to that in Example 2.2, “Example output of a kdesrc-build run”:

% kdesrc-build
Updating kde-build-metadata (to branch master)
Updating sysadmin-repo-metadata (to branch master)

Building libdbusmenu-qt (1/200)
        No changes to libdbusmenu-qt source, proceeding to build.
        Compiling... succeeded (after 0 seconds)
        Installing.. succeeded (after 0 seconds)

Building taglib (2/200)
        Updating taglib (to branch master)
        Source update complete for taglib: 68 files affected.
        Compiling... succeeded (after 0 seconds)
        Installing.. succeeded (after 0 seconds)

Building extra-cmake-modules from <module-set at line 32> (3/200)
        Updating extra-cmake-modules (to branch master)
        Source update complete for extra-cmake-modules: 2 files affected.
        Compiling... succeeded (after 0 seconds)
        Installing.. succeeded (after 0 seconds)

        ...

Building kdevelop from kdev (200/200)
        Updating kdevelop (to branch master)
        Source update complete for kdevelop: 29 files affected.
        Compiling... succeeded (after 1 minute, and 34 seconds)
        Installing.. succeeded (after 2 seconds)

<<<  PACKAGES SUCCESSFULLY BUILT  >>>
Built 200 modules

Your logs are saved in /home/kde-src/kdesrc/log/2018-01-20-07

Depending on how many modules you are downloading, it is possible that kdesrc-build will not succeed the first time you compile KDE software. Do not despair!

kdesrc-build logs the output of every command it runs. By default, the log files are kept in ~/kdesrc/log. To see what the caused an error for a module in the last kdesrc-build command, usually it is sufficient to look at ~/kdesrc/log/latest/module-name/error.log.

In that file, you will see the error that caused the build to fail for that module. If the file says (at the bottom) that you are missing some packages, try installing the package (including any appropriate -dev packages) before trying to build that module again. Make sure that when you run kdesrc-build again to pass the --reconfigure option so that kdesrc-build forces the module to check for the missing packages again.

Or, if the error appears to be a build error (such as a syntax error, “incorrect prototype”, “unknown type”, or similar) then it is probably an error with the KDE source, which will hopefully be resolved within a few days. If it is not resolved within that time, feel free to mail the (kde-devel kde.org) mailing list (subscription may be required first) in order to report the build failure.

You can find more common examples of things that can go wrong and their solutions, as well as general tips and strategies to build KDE software in the Build from Source.

On the other hand, assuming everything went well, you should have a new KDE install on your computer, and now it is simply a matter of running it, described next in the section called “Setting the Environment to Run Your KDE Plasma™ Desktop”.