Building Krita from Source

If you want to help developing Krita, or if you want to run the latest version of Krita on macOS, you need to know how to build Krita yourself. If you merely want to run the latest version of Krita on Windows or Linux, to test a bug or play with, you can use the nightly build for Windows or the nightly build for Linux

You can build Krita on Linux, Windows and OSX. The libraries Krita needs (for instance to load and save various image types) are called dependencies.

Linux is the easiest operating system to build Krita on because all the libraries that Krita needs are available on most recent Linux distributions. For an easy guide to building Krita see Building Krita on Linux for Cats

On OSX you can use tools like homebrew to get the dependencies, or build the dependencies manually. Building the dependencies manually is recommended because we have a number of changes to the source for libraries to make them function better with Krita.

On Windows you will have to build the dependencies yourself.

The build instructions for OSX/macOS and Windows are maintained as part of Krita’s source code repository. You will need to VERY carefully follow these instructions.

Building on Linux

This page only deals with building Krita on Linux. However, some remarks are the same for all operating systems, especially when it comes to running cmake and dealing with errors. You need to be familiar with using a terminal.

There are two options: you can either build Krita in your home directory, or use Docker, which makes setting up a development environment easier.

Preparing your development environment

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The most convenient layout is as follows:

  • $HOME/kritadev/krita – the source code

  • $HOME/kritadev/build – the location where you compile krita

  • $HOME/kritadev/install – the location where you install krita to and run krita from

we will call the “kritadev” folder your build root.

Note: type in what’s shown after ‘>’ in the following commands

you@yourcomputer:~>mkdir kritadev
you@yourcomputer:~/>cd kritadev
you@yourcomputer:~/kritadev> mkdir build
you@yourcomputer:~/kritadev> mkdir install

Getting the Source Code

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Open a terminal and enter the build root. Clone Krita from kde’s git infrastructure (not github):

you@yourcomputer:~/kritadev> git clone git://anongit.kde.org/krita.git

Configuring the Build

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you@yourcomputer:~/kritadev> cd build

Krita uses cmake (https://cmake.org) to define how Krita is built on various platforms. You first need to run cmake to generate the build system, in the kritadevs/build directory, then run make to make Krita, then run make install to install krita.

you@yourcomputer:~/kritadev/build>cmake ../krita -DCMAKE_INSTALL_PREFIX=/path/to/kritadev/install  -DCMAKE_BUILD_TYPE=RelWithDebInfo
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Unless you have installed all the dependencies Krita needs, on first running cmake, cmake will complain about missing dependencies. For instance:

-- The following RECOMMENDED packages have not been found:

* GSL, <http://www.gnu.org/software/gsl>
Required by Krita's Transform tool.

This is not an error, and you can fix this by installing the missing package using your distribution’s package manager. Do not download these packages manually from the source website and build them manually. Do use your distribution’s package manager to find the right packages.

For example, for Ubuntu, you can start with:

you@yourcomputer:~/kritadev/build>apt-get build-dep krita

Which will install all the dependencies of the version of Krita in the repositories.

However, the development version might use different dependencies, to find these, you can use apt-cache search:

you@yourcomputer:~/kritadev/build>apt-cache search quazip
libquazip-dev - C++ wrapper for ZIP/UNZIP (development files, Qt4 build)
libquazip-doc - C++ wrapper for ZIP/UNZIP (documentation)
libquazip-headers - C++ wrapper for ZIP/UNZIP (development header files)
libquazip1 - C++ wrapper for ZIP/UNZIP (Qt4 build)
libquazip5-1 - C++ wrapper for ZIP/UNZIP (Qt5 build)
libquazip5-dev - C++ wrapper for ZIP/UNZIP (development files, Qt5 build)
libquazip5-headers - C++ wrapper for ZIP/UNZIP (development header files, Qt5 build)

You will want to get the ‘dev’ library here, because you’re doing dev, and then Krita is using Qt5, so select that one. If this doesn’t help, check the Ubuntu packages search.

If all dependencies have been installed, cmake will output something like this:

-- Configuring done
-- Generating done
-- Build files have been written to: /home/boud/dev/b-krita

Until that is shown, cmake has not succeeded and you cannot build Krita. When this is shown, you can build Krita:

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you@yourcomputer:~/kritadev/build> make

You can speed this up by enabling multithreading. To do so, you first figure out how many threads your processor can handle:

cat /proc/cpuinfo | grep processor | wc -l

Then, add the resulting number with -j (for ‘Jobs’) at the end, so for example:

you@yourcomputer:~/kritadev/build> make -j4

Installing

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When the build has fully succeeded, you can install:

you@yourcomputer:~/kritadev/build> make install

And when that is complete, you can run Krita:

you@yourcomputer:~/kritadev/build>../install/bin/krita

Environment Variables

Now, to get Krita to work by just typing krita into the terminal, we’ll need to set up some environment variables. This will allow your system to know where Krita is located.

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Let’s show to your system the right path, inside a terminal, copy line by line :

export KDEDIRS=$HOME/kritadev/install:$KDEDIRS
export PATH=$HOME/kritadev/install/bin:$PATH

You will now be able to run Krita by typing krita into the terminal.

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Environment variables are never permanent. So we need to configure the system to set them each time you login. To set them at any login, write them with your favorite text editor at the end of your ~/.profile file (on certain distributions, the profile is named xprofile, check the hidden files in your home/your-user-name folder).

Updating

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Now, Krita is in constant development, so you will want to update your build from time to time. Maybe a cool feature got in, or a bug was fixed, or you just want the latest source.

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First, we get the new source from the git repository:

you@yourcomputer:~> cd ~/kritadev/krita/
you@yourcomputer:~/kritadev/krita> git pull

If you want to get the code from a specific branch, you will need to checkout that branch first:

you@yourcomputer:~/kritadev/krita> git checkout <name of the branch>
you@yourcomputer:~/kritadev/krita> git pull
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Then, we build again:

you@yourcomputer:~/kritadev/krita> cd ~/kritadev/build/
you@yourcomputer:~/kritadev/build> make install

If you update daily, you might want to automate these command by making your own minimal bash script.

Trouble Shooting

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The recent development version might break, or sometime be just unusable. Experimental changes are made daily.

This will affect your productivity if you don’t know how to ‘go back in time’ (for example, your favorite brush doesn’t work anymore).

But if you know how to do it, no issue can really affect you, because you know how to come back to a previous state.

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To travel the source in time we need to read the timeline history. The terminal tool for it is git log.

you@yourcomputer:~> cd ~/kritadev/krita/
you@yourcomputer:~/kritadev/krita> git log

With git log, you can consult all the last changes to the code, the ‘commit’. What we’re interested in is the long identification number, the ‘git hash’ (such as cca5819b19e0da3434192c5b352285b987a48796). You can scroll the git log, copy the ID number then quit(letter Q on keyboard). Then time-travel in your source directory:

you@yourcomputer:~/kritadev/krita> git checkout cca5819b19e0da3434192c5b352285b987a48796
you@yourcomputer:~/kritadev/krita> git pull

And, we build again:

you@yourcomputer:~/kritadev/krita> cd ~/kritadev/build/
you@yourcomputer:~/kritadev/build> make install
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To update again to the actual and ‘fresh from a minute ago’ source-code named master, simply ask git to come back to it with git checkout then pull to update :

you@yourcomputer:~/kritadev/krita> git checkout master
you@yourcomputer:~/kritadev/krita> git pull

Common problems

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Outside of the source being unstable, there’s the following common problems:

  • The most common problem is a missing dependency. Install it. A missing dependency is not an “error” that you need to report to the other Krita developers.

  • A dependency can also be too old. CMake will report when the version of a dependency is too old. That is also not an “error”. You might need to update your Linux installation to a newer version.

  • You can also have a successful build, then update your linux installation, and then find that Krita no longer builds. A library got updated, and you need to remove the CMakeCache.txt file in your build dir and run cmake again.

  • Sometimes, changes in Krita’s source code from git revision to git revision make it necessary to make your installation and/or build dir empty and build from scratch. One example is where a plugin is removed from Krita; the plugin will be in your install dir, and won’t get updated when Krita’s internals change.