Developing Krita in Visual Studio Code, part 1

Hi all! As part of our Community Bonding period, I wanted to share my experience setting up a development environment for Krita. We already have David Revoy’s post and the official, updated documentation. However, they only cover the setup process in Linux.

I’ll show you how to set Krita up in Visual Studio Code, under the three major desktop OSes: Linux, Windows, and macOS. For the latter two, I’ll show you how to use the same build scripts maintainers use for building the releases. We’ll take advantage of Visual Studio Code’s Tasks, so you do the hard work once, and then you’ll be able to compile dependencies AND run Krita in a few keystrokes!

Today’s post will tell you how to set Visual Studio Code up in Linux.

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In the spirit of David’s post and Krita’s docs, this post has the following sections:

• Preparing your development environment
• Getting the Source Code
• Getting the Libraries
• Configuring the Build
• Running Krita
• Updating
• Troubleshooting

So, without further ado, let’s begin with Linux!

A warning: this is a distilled version of the official, updated documentation. It’s optimized to set you up under Visual Studio Code.

Preparing your development environment

As I’ve said previously, the process in Linux is really well documented, so I’ll go straight into the itty bits.

We’ll set up a main folder called krita in our home directory. Inside it, we’ll create the following subfolders:

• $HOME/krita/build – the build files
• $HOME/krita/install – the installation directory

mkdir ~/krita
cd ~/krita
mkdir ./build
mkdir ./install

Getting the Source Code

We’ll grab a copy of the source code from KDE’s GitLab instance. Install Git from your package manager, e.g. for Debian or Ubuntu, sudo apt-get install git, and sudo pacman -Syu git for Manjaro and Arch). Then, let’s go to our krita folder

cd ~/krita

and run:

git clone https://invent.kde.org/kde/krita.git src

Getting the Libraries

Each Linux distribution has its own way to get Krita’s dependencies. In Debian-based distros, you should be able to pull them all at once, by running:

sudo apt-get build-dep krita

For others, like Manjaro (the one I’m using right while writing this post), you’ll need to get the list of dependencies from your package manager. For instance, in Manjaro you can use the expac tool:

expac -S "%D %o" krita

We set the -S option to query the sync database itself, and the string "%D %o" tells expac to list all dependencies, both required (%d) and optional (%o). Now, you can feed the list to pacman for installation by running:

sudo pacman -Sy $(expac -S "%D %o" krita)

Before moving on, make sure you have a working compiler! In Debian-based distros, run:

sudo apt-get install build-essential

In Arch and derivatives,

sudo pacman -Sy base-devel

should do the trick.

Configuring the Build

This is, by far, the most difficult part of our journey. You must install first the CMake build system (sudo apt-get install cmake, sudo pacman -Sy cmake), and inside Visual Studio Code, the CMake Tools extension.

Now, open our krita folder under Visual Studio Code,

code ~/krita

open the Command Palette (Ctrl+Shift+P), and select Preferences: Open Workspace Settings (JSON).

A JSON file will open, where you can set this workspace’s preferences. These are its contents on my machine:

{
    "cmake.configureSettings": {
        "BUILD_TESTING": false,
        //"PYQT_SIP_DIR_OVERRIDE": "/usr/lib/python3.8/site-packages/PyQt5/bindings/",
        "BUILD_KRITA_QT_DESIGNER_PLUGINS": true,
    },
    "cmake.parallelJobs": 12,
    "cmake.configureOnOpen": true,
    "cmake.clearOutputBeforeBuild": true,
    "cmake.installPrefix": "${workspaceFolder}/install",
    "cmake.sourceDirectory": "${workspaceFolder}/src"
}

• The cmake.configureSettings variable sets configuration-time environment variables.
  • BUILD_TESTING tells CMake to build Krita’s testing suite. I’ve set it to false so that it’s skipped.
  • PYQT_SIP_DIR_OVERRIDE is a fix you’ll need if you want to build Krita with Python support. Since Manjaro moves Python libraries where Krita cannot find them, I have to tell it where they are first. If you find this error: sip: Unable to find file "QtCore/QtCoremod.sip", uncomment this line.
  • BUILD_KRITA_QT_DESIGNER_PLUGINS tells CMake to build Krita’s UI components so that you can use them with Qt Designer. Disable if you won’t do UX development.
• cmake.parallelJobs sets how many parallel jobs you want your CPU to run. Mine is a 8-core, 16-thread Ryzen box, so I set 12 to have some breathing space. Set to 0 if you want to let CMake decide.
• cmake.configureOnOpen runs the configuration step every time you open this workspace.
• cmake.clearOutputBeforeBuild cleans the Output tab before starting the build.
• cmake.installPrefix tells CMake to install Krita to the ~/krita/install directory we created earlier.
• cmake.sourceDirectory tells CMake where we cloned Krita’s repository to.

With everything set, open the Command Palette again, select CMake: Build Target, install, and off you go!

Running Krita

You’ll probably want to run Krita inside a debugger. Good news is that you can do it from the comfort of Visual Studio Code, through a Launch task!

Open the Command Palette again, and select Debug: Open launch.json. My configuration adds a target called (gdb) Start:

{
    // https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(gdb) Start",
            "type": "cppdbg",
            "request": "launch",
            "program": "${workspaceFolder}/install/bin/krita",
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [
                {
                    "name": "LD_LIBRARY_PATH",
                    "value": "${workspaceFolder}/install/lib/"
                }
            ],
            "externalConsole": false,
            "internalConsoleOptions": "openOnSessionStart",
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty printing for GDB",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ],
        }
    ]
}

The most important bits are:

• program: it points to the krita executable, installed inside our install subdirectory;
• environment: we have to show our debugger the right path to Krita’s libraries, through the LD_LIBRARY_PATH environment variable.

After this, you can launch Krita by just pressing F5! Or also by opening the Command Palette, and selecting Debug: Start Debugging.

Updating

Thanks to Git, this is really easy. Go to our src folder and pull the last changes:

cd ~/krita/src
git pull

If you have a branch, check it out first:

cd ~/krita/src
git checkout MY_BRANCH
git pull

Then build and install Krita. Open the Command Palette, select CMake: Build Target, install.

Troubleshooting

• Sometimes, you’ll be unable to set Build tasks up. If this option doesn’t appear, it’s usually because your Visual Studio Code has User tasks already configured. Try opening the suggested “echo” task, delete it, and try again.

Tomorrow, I will tell you how to do these steps under macOS. If you experience any issues, please do ping me! amyspark @ #krita on Freenode.

Cheers,

~amyspark