Beyond Linux® From Scratch (systemd Edition) - Version 11.3

Chapter 25. Graphical Environment Libraries

Qt-5.15.8

Introduction to Qt5

Qt5 is a cross-platform application framework that is widely used for developing application software with a graphical user interface (GUI) (in which cases Qt5 is classified as a widget toolkit), and also used for developing non-GUI programs such as command-line tools and consoles for servers. One of the major users of Qt is KDE Frameworks 5 (KF5).

This package is known to build and work properly using an LFS 11.3 platform.

Package Information

Additional Downloads

Qt5 Dependencies

Required

Xorg Libraries

Recommended

alsa-lib-1.2.8, make-ca-1.12, Cups-2.4.2, double-conversion-3.2.1, GLib-2.74.5, gst-plugins-base-1.22.0 (QtMultimedia backend), HarfBuzz-7.0.0, ICU-72.1, JasPer-4.0.0, libjpeg-turbo-2.1.5.1, libmng-2.0.3, libpng-1.6.39, libtiff-4.5.0, libwebp-1.3.0, libxkbcommon-1.5.0, Mesa-22.3.5, mtdev-1.1.6, pcre2-10.42, SQLite-3.40.1, Wayland-1.21.0 (Mesa must be built with Wayland EGL backend), xcb-util-image-0.4.1, xcb-util-keysyms-0.4.1, xcb-util-renderutil-0.3.10, and xcb-util-wm-0.4.2

Optional

BlueZ-5.66 (for sdpscanner, and at runtime for QtConnectivity module), ibus-1.5.27, libinput-1.22.1, MariaDB-10.6.12 or MySQL, pciutils-3.9.0, PostgreSQL-15.2, PulseAudio-16.1, SDL2-2.26.3, unixODBC-2.3.11, assimp, Flite, Firebird, FreeTDS, libproxy, OpenAL, speech-dispatcher, tslib, and Vulkan

User Notes: https://wiki.linuxfromscratch.org/blfs/wiki/qt5

Setting the installation prefix

Installing in /opt/qt5

The BLFS editors recommend installing Qt5 in a directory other than /usr, ie /opt/qt5. To do this, set the following environment variable: 

export QT5PREFIX=/opt/qt5
[Tip]

Tip

Sometimes, the installation paths are hardcoded into installed files. This is the reason why /opt/qt5 is used as installation prefix instead of /opt/qt-5.15.8. To create a versioned Qt5 directory after the installation is complete, you may rename the directory and create a symlink: 

mkdir -pv /opt/qt-5.15.8
ln -sfnv qt-5.15.8 /opt/qt5

Later on, you may want to install other versions of Qt5. To do that, just remove the symlink and use /opt/qt5 as the prefix again. Which version of Qt5 you use depends only on where the symlink points.

[Note]

Note

If qca-2.3.5 has been installed and you are reinstalling or updating this package, then qca will need to be reinstalled.

Installation of Qt5

[Warning]

Warning

If Qt5 is being reinstalled into the same directory as an existing instance, run the commands done by root, such as make install, from a console or non-Qt5 based window manager. It overwrites Qt5 libraries that should not be in use during the install process.

[Caution]

Caution

If you did not install some of the recommended dependencies, examine ./configure --help output to check how to disable them or use internal versions bundled in the source tarball.

[Note]

Note

The build time and space required for the full Qt5 is quite long. The instructions below do not build the tutorials and examples. Removing the -nomake line will create a complete build.

[Note]

Note

The BLFS editors do not recommend installing Qt5 into the /usr hierarchy because it becomes difficult to find components and to update to a new version. If you do want to install Qt5 in /usr, the directories need to be specified explicitly. In this case, set QT5PREFIX=/usr and add the following to the configure arguments below: 

            -archdatadir    /usr/lib/qt5                \
            -bindir         /usr/bin                    \
            -plugindir      /usr/lib/qt5/plugins        \
            -importdir      /usr/lib/qt5/imports        \
            -headerdir      /usr/include/qt5            \
            -datadir        /usr/share/qt5              \
            -docdir         /usr/share/doc/qt5          \
            -translationdir /usr/share/qt5/translations \
            -examplesdir    /usr/share/doc/qt5/examples

First apply a patch to pull in the fixes curated by kde for those modules which are required by packages mentioned in this book: 

patch -Np1 -i ../qt-everywhere-opensource-src-5.15.8-kf5-1.patch

The patch is supposed to be used in a git repository, because the behavior of the configure command below is changed in this case. It is enough to create a .git directory in the qmake directory, where the configure script is run: 

mkdir -pv qtbase/.git

Install Qt5 by running the following commands: 

./configure -prefix $QT5PREFIX                        \
            -sysconfdir /etc/xdg                      \
            -confirm-license                          \
            -opensource                               \
            -dbus-linked                              \
            -openssl-linked                           \
            -system-harfbuzz                          \
            -system-sqlite                            \
            -nomake examples                          \
            -no-rpath                                 \
            -journald                                 \
            -skip qtwebengine                         &&
make

This package does not come with a test suite.

Now, as the root user: 

make install

Remove references to the build directory from installed library dependency (prl) files by running the following command as the root user: 

find $QT5PREFIX/ -name \*.prl \
   -exec sed -i -e '/^QMAKE_PRL_BUILD_DIR/d' {} \;

Install images and create the menu entries for installed applications. The QT5BINDIR variable is used here to point to the directory for the executable programs. If you have changed the bindir above, QT5BINDIR will need to be adjusted below. Be sure that the QT5BINDIR variable is defined in root's environment and as the root user: 

QT5BINDIR=$QT5PREFIX/bin

install -v -dm755 /usr/share/pixmaps/                  &&

install -v -Dm644 qttools/src/assistant/assistant/images/assistant-128.png \
                  /usr/share/pixmaps/assistant-qt5.png &&

install -v -Dm644 qttools/src/designer/src/designer/images/designer.png \
                  /usr/share/pixmaps/designer-qt5.png  &&

install -v -Dm644 qttools/src/linguist/linguist/images/icons/linguist-128-32.png \
                  /usr/share/pixmaps/linguist-qt5.png  &&

install -v -Dm644 qttools/src/qdbus/qdbusviewer/images/qdbusviewer-128.png \
                  /usr/share/pixmaps/qdbusviewer-qt5.png &&

install -dm755 /usr/share/applications &&

cat > /usr/share/applications/assistant-qt5.desktop << EOF
[Desktop Entry]
Name=Qt5 Assistant
Comment=Shows Qt5 documentation and examples
Exec=$QT5BINDIR/assistant
Icon=assistant-qt5.png
Terminal=false
Encoding=UTF-8
Type=Application
Categories=Qt;Development;Documentation;
EOF

cat > /usr/share/applications/designer-qt5.desktop << EOF
[Desktop Entry]
Name=Qt5 Designer
GenericName=Interface Designer
Comment=Design GUIs for Qt5 applications
Exec=$QT5BINDIR/designer
Icon=designer-qt5.png
MimeType=application/x-designer;
Terminal=false
Encoding=UTF-8
Type=Application
Categories=Qt;Development;
EOF

cat > /usr/share/applications/linguist-qt5.desktop << EOF
[Desktop Entry]
Name=Qt5 Linguist
Comment=Add translations to Qt5 applications
Exec=$QT5BINDIR/linguist
Icon=linguist-qt5.png
MimeType=text/vnd.trolltech.linguist;application/x-linguist;
Terminal=false
Encoding=UTF-8
Type=Application
Categories=Qt;Development;
EOF

cat > /usr/share/applications/qdbusviewer-qt5.desktop << EOF
[Desktop Entry]
Name=Qt5 QDbusViewer
GenericName=D-Bus Debugger
Comment=Debug D-Bus applications
Exec=$QT5BINDIR/qdbusviewer
Icon=qdbusviewer-qt5.png
Terminal=false
Encoding=UTF-8
Type=Application
Categories=Qt;Development;Debugger;
EOF

Some packages such as VLC-3.0.18 look for certain executables with a -qt5 suffix. Run the following command as the root user to create the necessary symlinks: 

for file in moc uic rcc qmake lconvert lrelease lupdate; do
  ln -sfrvn $QT5BINDIR/$file /usr/bin/$file-qt5
done

Command Explanations

sed ...: Allows using Python 3 instead of Python 2. This command destroys the build for QtWebEngine, so do not use it if you remove the -skip qtwebengine switch.

-confirm-license: Accept license without prompting user during configuration.

-opensource: Install the opensource version of Qt.

-nomake examples: This switch disables building of the example programs included in the source tarball. Remove it if you want to build them.

-system-sqlite: This switch enables use of the system version of SQLite.

-dbus-linked -openssl-linked: These switches enable explicit linking of the D-Bus and OpenSSL libraries into Qt5 libraries instead of dlopen()-ing them.

-journald: This switch allows to send Qt messages to the journald logging system.

-skip qtwebengine: This switch disables building the QtWebEngine. The BLFS editors have chosen to build qtwebengine-5.15.12 separately.

-system-harfbuzz: This switch enables use of the system version of Harfbuzz.

Configuring Qt5

Configuration Information

If Sudo-1.9.13p1 is installed, QT5DIR should be available to the super user as well. Execute the following commands as the root user: 

cat > /etc/sudoers.d/qt << "EOF"
Defaults env_keep += QT5DIR
EOF

If you installed Qt5 in /usr

If you installed Qt5 in /usr, create an environment variable needed by certain packages. As the root user: 

cat > /etc/profile.d/qt5.sh << "EOF"
# Begin /etc/profile.d/qt5.sh

QT5DIR=/usr
export QT5DIR
pathappend $QT5DIR/bin

# End /etc/profile.d/qt5.sh
EOF

If you did not install Qt5 in /usr

If you installed Qt5 in a location other than /usr, you need to update the following configuration files so that Qt5 is correctly found by other packages and system processes.

As the root user, update the /etc/ld.so.conf file and the dynamic linker's run-time cache file: 

cat >> /etc/ld.so.conf << EOF
# Begin Qt addition

/opt/qt5/lib

# End Qt addition
EOF

ldconfig

As the root user, create the /etc/profile.d/qt5.sh file: 

cat > /etc/profile.d/qt5.sh << "EOF"
# Begin /etc/profile.d/qt5.sh

QT5DIR=/opt/qt5

pathappend $QT5DIR/bin           PATH
pathappend $QT5DIR/lib/pkgconfig PKG_CONFIG_PATH

export QT5DIR

# End /etc/profile.d/qt5.sh
EOF

Contents

Installed Programs: assistant, balsam, canbusutil, designer, fixqt4headers.pl, lconvert, linguist, lprodump, lrelease, lrelease-pro, lupdate, lupdate-pro, meshdebug, moc, pixeltool, qcollectiongenerator, qdbus, qdbuscpp2xml, qdbusviewer, qdbusxml2cpp, qdistancefieldgenerator, qdoc, qgltf, qhelpgenerator, qlalr, qmake, qml, qmlcachegen, qmleasing, qmlformat, qmlimportscanner, qmllint, qmlmin, qmlplugindump, qmlpreview, qmlprofiler, qmlscene, qmltestrunner, qmltime, qmltyperegistrar, qscxmlc, qtattributionscanner, qtdiag, qtpaths, qtplugininfo, qtwaylandscanner, qvkgen, rcc, repc, sdpscanner, syncqt.pl, tracegen, uic, xmlpatterns, and xmlpatternsvalidator
Installed Libraries: libQt53DAnimation.so, libQt53DCore.so, libQt53DExtras.so, libQt53DInput.so, libQt53DLogic.so, libQt53DQuick.so, libQt53DQuickAnimation.so, libQt53DQuickExtras.so, libQt53DQuickInput.so, libQt53DQuickRender.so, libQt53DQuickScene2D.so, libQt53DRender.so, libQt5AccessibilitySupport.a, libQt5Bluetooth.so, libQt5Bodymovin.so, libQt5Bootstrap.a, libQt5Charts.so, libQt5Concurrent.so, libQt5Core.so, libQt5DataVisualization.so, libQt5DBus.so, libQt5DesignerComponents.so, libQt5Designer.so, libQt5DeviceDiscoverySupport.a, libQt5EdidSupport.a, libQt5EglFSDeviceIntegration.so, libQt5EglFsKmsSupport.so, libQt5EglSupport.a, libQt5EventDispatcherSupport.a, libQt5FbSupport.a, libQt5FontDatabaseSupport.a, libQt5Gamepad.so, libQt5GlxSupport.a, libQt5Gui.so,libQt5Help.so, libQt5InputSupport.a, libQt5KmsSupport.a, libQt5LinuxAccessibilitySupport.a, libQt5Location.so, libQt5Multimedia.so, libQt5MultimediaGstTools.so, libQt5MultimediaQuick.so, libQt5MultimediaWidgets.so, libQt5Network.so, libQt5NetworkAuth.so, libQt5Nfc.so, libQt5OpenGLExtensions.a, libQt5OpenGL.so, libQt5PacketProtocol.a, libQt5PlatformCompositorSupport.a, libQt5Positioning.so, libQt5PositioningQuick.so, libQt5PrintSupport.so, libQt5Purchasing.so, libQt5Qml.so, libQt5QmlDebug.a, libQt5QmlDevTools.a, libQt5QmlModels.so, libQt5QmlWorkerScript.so, libQt5Quick.so, libQt5Quick3D.so, libQt5Quick3DAssetImport.so, libQt5Quick3DRender.so, libQt5Quick3DRuntimeRender.so, libQt5Quick3DUtils.so, libQt5QuickControls2.so, libQt5QuickParticles.so, libQt5QuickShapes.so, libQt5QuickTemplates2.so, libQt5QuickTest.so, libQt5QuickWidgets.so, libQt5RemoteObjects.so, libQt5Script.so, libQt5ScriptTools.so, libQt5Scxml.so, libQt5Sensors.so, libQt5SerialBus.so, libQt5SerialPort.so, libQt5ServiceSupport.a, libQt5Sql.so, libQt5Svg.so, libQt5Test.so, libQt5TextToSpeech.so, libQt5ThemeSupport.a, libQt5UiTools.a, libQt5VirtualKeyboard.so, libQt5WaylandClient.so, libQt5WaylandCompositor.so, libQt5WebChannel.so, libQt5WebSockets.so, libQt5WebView.so, libQt5Widgets.so, libQt5X11Extras.so, libQt5XcbQpa.so, libQt5XkbCommonSupport.a, libQt5Xml.so, libQt5XmlPatterns.so, and several plugins under /opt/qt5/{plugins,qml}
Installed Directories: /usr/include/qt5, /usr/lib/qt5, /usr/share/doc/qt5, and /usr/share/qt5 OR /opt/qt5 and /opt/qt-5.15.8

Short Descriptions

assistant

is a tool for presenting on-line documentation

balsam

is a tool to convert 3D scenes from various creation tools to QML format, for use by the new QtQuick 3D library

canbustil

is a tool to deal with arbitrary CAN bus frames. A Controller Area Network (CAN) is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer

designer

is a full-fledged GUI builder. It includes powerful features such as preview mode, automatic widget layout, support for custom widgets, and an advanced property editor

fixqt4headers.pl

is a script to replace all Qt 4 style includes with Qt 5 includes

lconvert

is part of Qt5's Linguist tool chain. It can be used as a standalone tool to convert and filter translation data files

linguist

provides support for translating applications into local languages

lrelease

is a simple command line tool. It reads XML-based translation file in TS format and produces message files used by the application

lrelease-pro

extracts project information from qmake projects and passes it to lrelease

lupdate

finds the translatable strings in the specified source, header and Qt Designer interface files, and stores the extracted messages in translation files to be processed by lrelease

lupdate-pro

reads a Qt project file, an passes the collected information to lupdate

meshdebug

displays information about qtquick-3d mesh files

moc

generates Qt meta object support code

pixeltool

is a desktop magnifier and as you move your mouse around the screen it will show the magnified contents in its window

qcollectiongenerator

processes and converts Qt help files

qdbuscpp2xml

takes a C++ source file and generates a D-Bus XML definition of the interface

qdbus

lists available services, object paths, methods, signals, and properties of objects on a bus

qdbusviewer

is a graphical D-Bus browser

qdbusxml2cpp

is a tool that can be used to parse interface descriptions and produce static code representing those interfaces,

qdistancefieldgenerator

allows a font cache to be pregenerated for Text.QtRendering to speed up an application's startup if the user interface has a lot of text, or multiple fonts, or a large amount of distinct characters, e.g. in CJK writing systems

qdoc

is a tool used by Qt Developers to generate documentation for software projects

qgltf

imports a a variety of 3D model formats and exports into fast-to-load, optimized glTF assets embedded into Qt resource files

qhelpgenerator

is a tool used to generate a Qt compressed help file

qlalr

is a tool used to generate code from grammar specifications

qmake

uses information stored in project files to determine what should go in the makefiles it generates

qml

executes a QML file

qmlcachegen

supports the creation of cache files at build time

qmleasing

is a tool used to define the easing curves using an interactive curve editor

qmlformat

formats QML files according to the QML coding conventions

qmlimportscanner

is a tool used to import QML files from a directory

qmllint

is a syntax checker for QML files

qmlmin

removes comments and layout characters from a QML file

qmlplugindump

is a tool to create a qmltypes file

qmlpreview

is a tool used to analyze QML applications

qmlprofiler

is a tool which watches QML and JavaScript files on disk and updates the application live with any changes

qmlscene

is a utility that loads and displays QML documents even before the application is complete

qmltestrunner

is a tool used to make tests

qscxml

converts an input.scxml file to a header and cpp file

qtattributionsscanner

processes qt_attribution.json files in Qt sources

qtdiag

is a tool for reporting diagnostic information about Qt and its environment

qtpaths

is a tool to query Qt path information

qtplugininfo

dumps meta-data about Qt plugins in JSON format

qtwaylandscanner

converts Wayland specfiles to C++ headers and code needed for QtWayland

qvkgen

converts Vulkan specfiles to C++ headers and code

rcc

is a resource compiler used in conjunction with designer

repc

is the Replica Compiler, which generates QObject header files based on an API definition file

sdpscanner

performs a Session Description Protocol scan on a remote device, using the SDP server represented by the local Bluetooth device

syncqt.pl

is a script to create the forwarding headers in the include directories. It is an internal development tool

tracegen

is a trace generator for LTTng or ETW

uic

is a Qt user interface compiler

xmlpatterns

provides support for XPath, XQuery, XSLT, and XML Schema validation

xmlpatternsvalidator

is a tool used to validate XML documents