Over the past few months, I've been working on a side project to improve Meson sub-project support. The best stress test is to build projects on Windows, without msys2, because it has no dependencies or tools installed (e.g. pkg-config). Meson has to build everything itself from scratch.

Here are step-by-step instructions, starting from a fresh Windows 10 installation, on how to run a gtk4-demo application.

Install Visual Studio

Download from https://visualstudio.microsoft.com/vs/community. Make sure to check the box "Desktop development with C++".

Install Python >= 3.6

Download from https://www.python.org/downloads. Make sure to check the box "Add python to PATH".

Install Git for Windows

Download from https://gitforwindows.org. It asks many questions, however the default is always good enough, so next, next, next...

Open developer terminal

From the Windows start menu, search for x64 Native Tools Command Prompt for VS 2019. That will open a terminal configured to use MSVC x64 tools.

First let's create a directory where we'll fetch the source code:

mkdir C:\src
cd C:\src

Let's also configure git:

git config --global user.email "xavier.claessens@collabora.com"
git config --global user.name "Xavier Claessens"

Install Meson

Installing the latest release of Meson (requires >=0.57.0) can be done with a simple command:

C:\src>pip install meson

Fetch GTK4 source

Fetch gtk from git:

C:\src>git clone https://gitlab.gnome.org/GNOME/gtk.git
C:\src>cd gtk

At the time of writing !3135 is not yet merged, so we need to use my branch:

(Update March 22: This has now been merged so my branch is no longer needed.)

C:\src\gtk>git fetch https://gitlab.gnome.org/xclaesse/gtk.git meson-install-script
C:\src\gtk>git checkout -b meson-install-script FETCH_HEAD

Build GTK4 with all its dependencies

During the GTK4 configuration, Meson will download and configure all dependencies. Great efforts have been made across all dependencies to make them work out of the box on Windows.

C:\src\gtk>meson setup build --prefix C:/gnome
C:\src\gtk>meson compile -C build
C:\src\gtk>meson install -C build

Run gtk4-demo

That's all, you can now run demo applications!

C:\src\gtk>C:\gnome\bin\gtk4-demo.exe

It works out of the box on my VirtualBox machine, however on my physical PC with an intel GPU, I get a crash at startup:

Unhandled exception at 0x5211345E (ig4icd32.dll) in gtk4-demo.exe: 0xC0000005: Access violation reading location 0x00000050

This can be worked around by using cairo rendering:

C:\src\gtk>set GSK_RENDERER=cairo
C:\src\gtk>C:\gnome\bin\gtk4-demo.exe

Debug in Visual Studio

Since this is a complete build using MSVC, it is also fully debuggable.

• Open Visual Studio
• Click "Open a project or solution"
• Browse to C:\gnome\bin\gtk4-demo.exe
• Click "Start" button

If you break execution, or hit a crash, it will open the source code and you can debug step by step, see the value of any variable, whether it is in gtk or in any of its dependencies.

Debugging in Visual Studio.

What's next?

Here's a list of some of the items I would like to eventually look into:

• See if we can use GTK4 as sub-project of a real application. Which applications do we have that are ported to GTK4 already and runs on Windows? Gedit?
• Add GStreamer gst-build as a sub-project of GTK4 to build the media player? This would probably lead to a world record of number of Meson subprojects built at once.
• Add Windows CI to GTK4?

As usual, if you have any questions about GTK4 or GStreamer on Windows, or any other platform, please contact us!