Wednesday, December 17, 2014

kdesrc-build is a very useful tool, here's why

I've been thinking for some time about writing a post about my favorite tool for building, rebuilding, testing, fixing random parts of kde software and how I use it (many times a day, depending on the situation).

For anyone that doesn't know, kdesrc-build is a script, written in perl, it lives in extragear/utils/kdesrc-build in the kde project heirarchy and can be cloned from kde:kdesrc-build if you've got your ~/.gitconfig as follows (if you don't you should add it, go add it now, I'll wait):


[url "git://anongit.kde.org/"]
       insteadOf = kde:
[url "git@git.kde.org:"]
       pushInsteadOf = kde:
kdesrc-build is very useful in that running it with no arguments it will build all of your kde stack. This includes all the frameworks (including Qt if you want it to), all library dependencies that come from git.kde.org and all applications. To start using it, just clone it, build it (mkdir build, cd build, cmake ../, make, make install, or sudo make install if you aren't the owner of /usr/local yet) and you can run kdesrc-build from any path your terminal happens to be in. The one thing needed is a .kdesrc-buildrc file to tell it what you want to build, where you want it installed to, which build options etc. you want. This is pretty straightforward though and most of the kde stack is in include files you can add from your .kdesrc-buildrc itself. Mine looks like this:

# Adjust all these settings at will

global


 qtdir /usr
 # qtdir /home/jeremy/devel/kde/src/qt5bulid/qtbase
 source-dir /home/jeremy/devel/kde/src
 build-dir /home/jeremy/devel/kde/build
 kdedir /usr/local

 git-repository-base kde-projects kde:

 cxxflags -pipe -DQT_STRICT_ITERATORS -DQURL_NO_CAST_FROM_STRING -DQT_NO_HTTP -DQT_NO_FTP -Wformat -Werror=return-type -Wno-variadic-macros -Wlogical-op
 # WARNING: opensuse users need -DLIB_SUFFIX=64 here, as long as FindKDE4Internal.cmake is used
 #          if you're using a distro without "lib64", remove the option.
 # cmake-options -DKDE4_BUILD_TESTS=TRUE -DLIB_SUFFIX=64
 cmake-options -DBUILD_TESTING=TRUE -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_LIBDIR=lib

 make-options -j8
 #install-session-driver true
 branch-group kf5-qt5

end global

include devel/kde/src/extragear/utils/kdesrc-build/kf5-qt5-build-include

I go back and forth sometimes between distro packaged qt (in /usr) and my own built qt from git (in the other path) so I uncomment the one I want to use in those first few lines.

It's pretty simple and short, set 9 variables, include the kf5-qt5-build-include file and we're good to go. So for me, kdesrc-build with no arguments builds and installs many different kde applications, with their sources nicely organized under ~/devel/kde/src and their build folders easy to delete if needed in ~/devel/kde/build and installs into /usr/local where I have my XDG_* variables set to find applications, libraries, data, default configurations, etc. Also if some part of the workspace becomes deprecated and I need to remove old libraries, .desktop files, and such I can safely (from a terminal, not within X) nuke /usr/local/* and rerun kdesrc-build to rebuild everything that's current.

kdesrc-build frameworks - builds all the parts of kf5 itself.
kdesrc-build kdeedu - builds all the libraries and applications that have been ported to qt5/kf5 from kdeedu.
kdesrc-build --no-src kanagram - builds kanagram with my local changes for testing before committing the next feature, also useful to test patches from reviewboard (download, patch, kdesrc-build --no-src foo to build/install, run to test).
kdesrc-build --no-src khangman - builds whatever I've got checked out in kde/kdeedu/khangman at the time (currently an almost complete gsoc student's qml ui of khangman from his branch).
kdesrc-build --refresh-build - rebuilds everything with clean build folders using the cmake options from your .kdesrc-buildrc file, this is useful if you change these options and want to test them
kdesrc-build --refresh-build --no-src foo - rebuilds everything with a clean build and doesn't do any git updates, only tries to build what's on your local clone, this is useful when porting applications to kf5/qt5 to make sure cmake is reran when trying a build of local changes.

A good thing to know is that errors are all logged, and you can check them simply by checking source-dir/log/latest/foo/error.log (which symlinks to cmake.log, build.log, or install.log, depending where the error was).

One more nice thing, since kdesrc-build uses kde-project-metadata it can guess some projects from their location on projects.kde.org. So even if I don't have skrooge or some other extragear application in my .kdesrc-buildrc file or it's not in the included kf5-qt5-build-include file or whatnot, kdesrc-build skrooge will guess where skrooge comes from and clone it to the proper place in the heirarchy and build it.

In summary, kdesrc-build is useful for what it was created for, building the kde stack of software with your preferences.