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 and builds everything in one go. However, this small guide shows the alternative way, so called module build, which is more robust as it clones minimum subset of modules required for QtWebEngine and compiles each module separately. It is also very flexible way of building as you can try to compile newer QtWebEngine module with older qt modules. Compiling each module separately has also 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.

Obtain Qt6 source code

mkdir qt6
cd qt6

git clone git://code.qt.io/qt/qtbase.git
git clone git://code.qt.io/qt/qtshadertools.git
git clone git://code.qt.io/qt/qtdeclarative.git
git clone git://code.qt.io/qt/qtwebengine.git

cd qtwebenigne
git submodule init
git submodule update
cd ..

Note that web engine needs initialization of submodule.

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 barnches:

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

mkdir build
cd build
mkdir qtbase qtshadertools qtdeclarative qtwebengine

Configure and build qtbase

From out qtbase build directory we call configure from qtbase source directory to make prefix build, which means that we compile and than install to specific installation directory here /opt/qt/6.2

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

Here we do release build with no examples and no tests. For other configure options please refer to configure quide https://doc.qt.io/qt-6/configure-options.html

Note to speed up linking time for webengine we decided to use lld linker.

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

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

Configure and build other modules

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

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

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

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