QtWebEngine/Qt6Build

Building Qt6 WebEngine from Source

Please check platform notes for required dependencies https://doc.qt.io/qt-6/qtwebengine-platform-notes.html.

Qt builds can be done in top level manner, meaning that you clone qt5 main repository (git://code.qt.io/qt/qt5.git), which then initializes all the qt modules as sub-modules, configures all the modules and builds everything in one go. However, there is also the alternative way, so called module build, which is more robust as it configures, builds and installs each qt module separately.

This guide uses both approaches, first it clones minimum subset of modules required for QtWebEngine and compiles all modules required for webengine build in top level manner. Then it builds webengine module separately, so we are able to focus on webenigne build issues only.

  Note: Compiling each module separately has advantage that you can see configure and compilation issues just for given module, meaning that you can install missing dependencies and just reconfigure and recompile the problematic module instead of rerunning configuration for all modules.

Open the build shell

All the build commands we execute in a build shell / terminal.

On Windows platform Developer Command Prompt is required, therefore for example for Visual Studio Build Tools 2022 the correct setup requires:

call "C:\Program File (x86)\Microsoft Visial Studio\2022\BuildTools\VC\Auxilary\Build\vcvarsall.bat" amd64

  Note: The location of the script may vary please refer to the Microsoft documentation.

Obtain the Qt6 source code

Select the location for the source code and checkout the source:

Starting with Qt 6.8 you can simply clone qt5 repository and call 'init-repository' cmake script.

git clone git://code.qt.io/qt/qt5.git qt6
cd qt6
init-repository --module-subset=qtbase,qtshadertools,qtdeclarative,qtwebengine --no-resolve-deps

  Note: On Windows platform you should use 'init-repository.bat' instead of 'init-repository' command.

QtWebEngine needs initialization of the submodule:

cd qtwebenigne
git submodule init
git submodule update
cd ..

Select branches

Let's assume we want to compile Qt 6.2.4 with Qt WebEngine 6.4.3 Therefore, in qtbase, qtshadertools, qtdeclarative repositories we select branches:

git checkout origin/6.2.4

Where-else in qtwebengine

cd qtwebengine
git checkout origin/6.4.3
git submodule update
cd ..

Shadow build

It is a common practice to compile the project in separate build directory instead of doing in-source build, therefore we create the following build layout:

  Note: On Windows platform you should use 'md' instead of 'mkdir' command

mkdir build
cd build
mkdir qtbase qtshadertools qtdeclarative qtwebengine

Configure and build qtbase

From our qtbase 'build' directory we call the configure from qtbase 'source' directory to make prefix build, which means that we will compile and than install to the specific installation directory defined with 'prefix' argument.

On Linux the configure command line for the release builds with xcb might look like:

cd build/qtbase
../../qtbase/configure -opensource -confirm-license -release -nomake tests -nomake examples -xcb -opengl desktop -qpa xcb -no-pch -linker lld -prefix /opt/qt/6.2

  Note: To speed up linking time for WebEngine we decided to use lld linker.

On Windows the configure command line for the release build with debug info might look like:

cd build\qtbase
..\..\qtbase\configure.bat -opensource -confirm-license -release -force-debug-info -nomake tests -nomake examples -prefix C:\opt\qt\6.2

On Mac the configure command line for the release framework builds might look like:

cd build/qtbase
../../qtbase/configure -developer-build -nomake examples -release -force-debug-info -separate-debug-info -framework -prefix /opt/qt/6.2

or Mac universal build :

cd build/qtbase
../../qtbase/configure -nomake examples -release -force-debug-info -separate-debug-info -framework -prefix /opt/qt/6.2 -- -DCMAKE_OSX_ARCHITECTURES="x86_64;arm64"

  Note: For other configure options please refer to the configure guide https://doc.qt.io/qt-6/configure-options.html

To build and install qt base you just need to call cmake:

cmake --build . --parallel
cmake --install .

  Note: On Windows in case of debug and release build please use "ninja install" instead of "cmake --install ." due to cmake issue

Configure and build other modules

To configure and build other modules we use the qt-configure-module wrapper script from the installed qtbase module.

  Note: On Windows you might want to call 'C:\opt\qt\6.2\bin\qt-cofigure-module.bat' instead of 'qt-cofigure-module'

cd build/qtshadertools
/opt/qt/6.2/bin/qt-configure-module ../../qtshadertools
cmake --build . --parallel
cmake --install .
cd ..

cd qtdeclarative
/opt/qt/6.2/bin/qt-configure-module ../../qtdeclarative
cmake --build . --parallel
cmake --install .
cd ..

cd qtwebengine
/opt/qt/6.2/bin/qt-configure-module ../../qtwebengine
cmake --build . --parallel
cmake --install .
cd ..