Qt WebEngine compilation error

[Vidya H]

I am configuring Qt commercial code from https://codereview.qt-project.org/qt/tqtc-qt5, branch = tqtc/lts-5.15.7. I need webengine and have got a pdf generation requirement for my project.

I am using the below command for configuration:

LDFLAGS="-L/home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib -lstdc++" ~/tqtc-qt5/configure --verbose -platform linux-g++ -xplatform linux-arm-gnueabihf-g++ -device-option CROSS_COMPILE=/usr/bin/arm-linux-gnueabihf- -sysroot /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi -prefix /home/user/qt5-build -commercial -confirm-license -release -gui -widgets -no-dbus -opengl -linuxfb -sql-sqlite -nomake examples -nomake tests -webengine-printing-and-pdf -tslib

Config.summary file looks like this:

Building for: linux-arm-gnueabihf-g++ (arm, CPU features: <none>)
Target compiler: gcc 11.4.0
Configuration: cross_compile compile_examples enable_new_dtags largefile precompile_header shared shared rpath release c++11 c++14 c++17 c++1z concurrent reduce_exports stl
Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++17
  Using ccache ........................... no
  Using new DTAGS ........................ yes
  Relocatable ............................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. no
  Build parts ............................ libs
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... no
  Qt D-Bus directly linked to libdbus .... no
  Qt Gui ................................. yes
  Qt Network ............................. yes
  Qt Sql ................................. yes
  Qt Testlib ............................. yes
  Qt Widgets ............................. yes
  Qt Xml ................................. yes
Support enabled for:
  Using pkg-config ....................... yes
  udev ................................... yes
  Using system zlib ...................... yes
  Zstandard support ...................... yes
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... yes
  iconv .................................. no
  ICU .................................... yes
  Built-in copy of the MIME database ..... yes
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  PCRE2 .................................. yes
    Using system PCRE2 ................... no
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  OpenSSL 1.1 ............................ yes
  DTLS ................................... yes
  OCSP-stapling .......................... yes
  SCTP ................................... no
  Use system proxies ..................... yes
  GSSAPI ................................. no
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ yes
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  Text formats:
    HtmlParser ........................... yes
    CssParser ............................ yes
    OdfWriter ............................ yes
    MarkdownReader ....................... yes
      Using system libmd4c ............... no
    MarkdownWriter ....................... yes
  EGL .................................... yes
  OpenVG ................................. no
  OpenGL:
    Desktop OpenGL ....................... yes
    OpenGL ES 2.0 ........................ no
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
    OpenGL ES 3.2 ........................ no
  Vulkan ................................. yes
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... yes
  INTEGRITY HID .......................... no
  mtdev .................................. yes
  tslib .................................. yes
  xkbcommon .............................. yes
  X11 specific:
    XLib ................................. yes
    XCB Xlib ............................. yes
    EGL on X11 ........................... no
    xkbcommon-x11 ........................ yes
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. yes
  EGLFS details:
    EGLFS OpenWFD ........................ no
    EGLFS i.Mx6 .......................... no
    EGLFS i.Mx6 Wayland .................. no
    EGLFS RCAR ........................... no
    EGLFS EGLDevice ...................... yes
    EGLFS GBM ............................ yes
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... no
    EGLFS X11 ............................ no
  LinuxFB ................................ yes
  VNC .................................... yes
  XCB:
    Using system-provided xcb-xinput ..... yes
    Native painting (experimental) ....... no
    GL integrations:
      GLX Plugin ......................... yes
        XCB GLX .......................... yes
      EGL-X11 Plugin ..................... no
Qt Sql:
  SQL item models ........................ yes
Qt Widgets:
  GTK+ ................................... yes
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. no
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no
Qt Testlib:
  Tester for item models ................. yes
Serial Port:
  ntddmodm ............................... no
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
  SerialPort Support ..................... yes
Further Image Formats:
  JasPer ................................. no
  MNG .................................... no
  TIFF ................................... yes
    Using system libtiff ................. yes
  WEBP ................................... yes
    Using system libwebp ................. yes
Qt QML:
  QML network support .................... yes
  QML debugging and profiling support .... yes
  QML just-in-time compiler .............. yes
  QML sequence object .................... yes
  QML XML http request ................... yes
  QML Locale ............................. yes
Qt QML Models:
  QML list model ......................... yes
  QML delegate model ..................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Qt Quick Designer .......... yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  TableView item ......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  Repeater item .......................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
Qt Opcua:
  Open62541 .............................. yes
  Unified Automation C++ SDK ............. no
  Support for namespace 0 NodeId names ... yes
  Namespace 0 NodeIds generator .......... no
  mbedtls ................................ yes
  Support for global discovery server .... yes
QtQuick3D:
  Assimp ................................. yes
  System Assimp .......................... no
Qt Scxml:
  ECMAScript data model for QtScxml ...... yes
Qt Gamepad:
  SDL2 ................................... no
Qt 3D:
  Assimp ................................. yes
  System Assimp .......................... no
  Output Qt3D GL traces .................. no
  Use SSE2 instructions .................. no
  Use AVX2 instructions .................. no
  Aspects:
    Render aspect ........................ yes
    Input aspect ......................... yes
    Logic aspect ......................... yes
    Animation aspect ..................... yes
    Extras aspect ........................ yes
Qt 3D Renderers:
  OpenGL Renderer ........................ yes
  RHI Renderer ........................... no
Qt 3D GeometryLoaders:
  Autodesk FBX ........................... no
Qt Wayland Drivers:
  EGL .................................... yes
  Raspberry Pi ........................... no
  XComposite EGL ......................... no
  XComposite GLX ......................... yes
  DRM EGL ................................ yes
  libhybris EGL .......................... no
  Linux dma-buf server buffer integration . yes
  Vulkan-based server buffer integration . yes
  Shm emulation server buffer integration . yes
Qt Wayland Client Shell Integrations:
  xdg-shell .............................. yes
  xdg-shell unstable v5 (deprecated) ..... yes
  xdg-shell unstable v6 .................. yes
  ivi-shell .............................. yes
  wl-shell (deprecated) .................. yes
Qt Wayland Client ........................ yes
Qt Wayland Compositor .................... yes
Qt Wayland Compositor Layer Plugins:
  VSP2 hardware layer integration ........ no
Qt Bluetooth:
  BlueZ .................................. no
  BlueZ Low Energy ....................... no
  Linux Crypto API ....................... no
  Native Win32 Bluetooth ................. no
  WinRT Bluetooth API (desktop & UWP) .... no
  WinRT advanced bluetooth low energy API (desktop & UWP) . no
Qt Sensors:
  sensorfw ............................... no
Qt Quick Controls 2:
  Styles ................................. Default Fusion Imagine Material Universal
Qt Quick Templates 2:
  Hover support .......................... yes
  Multi-touch support .................... yes
Qt Positioning:
  Gypsy GPS Daemon ....................... no
  WinRT Geolocation API .................. no
Qt Location:
  Qt.labs.location experimental QML plugin . no
  Geoservice plugins:
    OpenStreetMap ........................ yes
    HERE ................................. yes
    Esri ................................. yes
    Mapbox ............................... yes
    MapboxGL ............................. yes
    Itemsoverlay ......................... yes
QtXmlPatterns:
  XML schema support ..................... yes
Qt Multimedia:
  ALSA ................................... yes
  GStreamer 1.0 .......................... yes
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. no
  PulseAudio ............................. yes
  Resource Policy (libresourceqt5) ....... no
  Windows Audio Services ................. no
  DirectShow ............................. no
  Windows Media Foundation ............... no
Qt TextToSpeech:
  Flite .................................. no
  Flite with ALSA ........................ no
  Speech Dispatcher ...................... no
Qt Tools:
  Qt Assistant ........................... yes
  Qt Designer ............................ yes
  Qt Distance Field Generator ............ yes
  kmap2qmap .............................. yes
  Qt Linguist ............................ yes
  Mac Deployment Tool .................... no
  makeqpf ................................ yes
  pixeltool .............................. yes
  qdbus .................................. yes
  qev .................................... yes
  Qt Attributions Scanner ................ yes
  qtdiag ................................. yes
  qtpaths ................................ yes
  qtplugininfo ........................... yes
  Windows deployment tool ................ no
  WinRT Runner Tool ...................... no
Qt Tools:
  QDoc ................................... no
Qt WebEngine Build Tools:
  Use System Ninja ....................... yes
  Jumbo Build Merge Limit ................ 8
  Developer build ........................ no
  Sanitizer .............................. no
  QtWebEngine required system libraries:
    fontconfig ........................... yes
    dbus ................................. yes
    nss .................................. yes
    khr .................................. yes
    glibc ................................ yes
  QtWebEngine required system libraries for qpa-xcb:
    x11 .................................. yes
    libdrm ............................... yes
    xcomposite ........................... yes
    xcursor .............................. yes
    xi ................................... yes
    xproto (glproto) ..................... yes
    xtst ................................. yes
    xkbfile .............................. yes
  Optional system libraries used:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . yes
    opus ................................. no
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... no
    glib ................................. yes
    zlib ................................. yes
    minizip .............................. no
    libevent ............................. no
    libxml2 and libxslt .................. no
    lcms2 ................................ no
    png .................................. yes
    JPEG ................................. yes
    harfbuzz ............................. yes
    freetype ............................. yes
Qt WebEngineCore:
  Embedded build ......................... yes
  Full debug information ................. no
  Pepper Plugins ......................... no
  Printing and PDF ....................... yes
  Proprietary Codecs ..................... no
  Spellchecker ........................... yes
  Native Spellchecker .................... no
  WebRTC ................................. no
  PipeWire over GIO ...................... no
  Geolocation ............................ yes
  WebChannel support ..................... yes
  Kerberos Authentication ................ no
  Extensions ............................. yes
  Support qpa-xcb ........................ yes
  Building v8 snapshot supported ......... yes
  Use ALSA ............................... yes
  Use PulseAudio ......................... yes
Qt WebEngineQml:
  Support Qt WebEngine Qml ............... yes
  UI Delegates ........................... yes
  Test Support ........................... no
Qt WebEngineWidgets:
  Support Qt WebEngine Widgets ........... yes
Qt PDF:
  Support V8 ............................. no
  Support XFA ............................ no
  Support XFA-BMP ........................ no
  Support XFA-GIF ........................ no
  Support XFA-PNG ........................ no
  Support XFA-TIFF ....................... no
Qt PDF Widgets:
  Support Qt PDF Widgets ................. yes

Note: PKG_CONFIG_LIBDIR automatically set to /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib/pkgconfig:/home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/share/pkgconfig:/home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib/arm-linux-gnueabihf/pkgconfig

Note: PKG_CONFIG_SYSROOT_DIR automatically set to /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi

Note: Disabling X11 Accessibility Bridge: D-Bus or AT-SPI is missing.

WARNING: QDoc will not be compiled, probably because libclang could not be located. This means that you cannot build the Qt documentation.

Either ensure that llvm-config is in your PATH environment variable, or set LLVM_INSTALL_DIR to the location of your llvm installation.
On Linux systems, you may be able to install libclang by installing the libclang-dev or libclang-devel package, depending on your distribution.
On macOS, you can use Homebrew's llvm package.
On Windows, you must set LLVM_INSTALL_DIR to the installation path.

WARNING: Thumb instruction set is required to build ffmpeg for QtWebEngine.

I am running make command after the successful configuration and getting output as below.

/usr/lib/gcc-cross/arm-linux-gnueabihf/11/../../../../arm-linux-gnueabihf/bin/ld: /home/user/qt5-build/qtbase/lib/libQt5Test.so: undefined reference to `std::condition_variable::wait(std::unique_lock<std::mutex>&)@GLIBCXX_3.4.30'
collect2: error: ld returned 1 exit status
make[3]: *** [Makefile:69: ../../bin/qmltestrunner] Error 1
make[3]: Leaving directory '/home/user/qt5-build/qtdeclarative/tools/qmltestrunner'
make[2]: *** [Makefile:359: sub-qmltestrunner-make_first] Error 2
make[2]: Leaving directory '/home/user/qt5-build/qtdeclarative/tools'
make[1]: *** [Makefile:75: sub-tools-make_first] Error 2
make[1]: Leaving directory '/home/user/qt5-build/qtdeclarative'
make: *** [Makefile:397: module-qtdeclarative-make_first] Error 2

Please help me to resolve the linker error and proceed further for installation. Let me know if full make log is required.

[SGaist]

Hi,

Since you have a commercial license, you should contact the Qt Company support.

[Vidya H]

Thank you @SGaist . I have tried the same using open source code and getting same errors. Could you please help me?

[SGaist]

The fact that you are using the open source sources does not change my initial suggestion: you have a commercial license so you can request the Qt Company's help.

Do you have multiple versions of libstdc++ in your sysroot ?

On a side note, your thread title is misleading, you haven't even reached webengine yet in your build.

[Vidya H]

I have reached out to the Qt company for help. However, I have a standard license and hence it will take 1-2 days for their response. I have only one version of libstdc++ in the sysroots. I am getting the linker errors only when I added the "-webengine-printing-and-pdf" to the configure command. Without this, I was able to configure and compile Qt from source. Could you please help me what am I missing? I am doing this for the first time.

My configure command looks like this:
LDFLAGS="-L/home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib -lstdc++" ~/tqtc-qt5/configure --verbose -platform linux-g++ -xplatform linux-arm-gnueabihf-g++ -device-option CROSS_COMPILE=/usr/bin/arm-linux-gnueabihf- -sysroot /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi -prefix /home/user/qt5-build -commercial -confirm-license -release -gui -widgets -no-dbus -opengl -linuxfb -sql-sqlite -nomake examples -nomake tests -webengine-printing-and-pdf -tslib

Below are the search results from the sysroots.

user@ip:~/ti-processor-sdk-linux-am335x-evm-09.01.00.001$ find . -name libstdc++.so*
./linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib/libstdc++.so.6
./linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib/libstdc++.so.6.0.29
./linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi/usr/lib/libstdc++.so
./linux-devkit/sysroots/x86_64-arago-linux/usr/lib/libstdc++.so.6
./linux-devkit/sysroots/x86_64-arago-linux/usr/lib/libstdc++.so.6.0.29
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/lib/libstdc++.so.6
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/lib/libstdc++.so.6.0.29-gdb.py
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/lib/libstdc++.so.6.0.29
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/lib/libstdc++.so
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/libc/usr/lib/libstdc++.so.6
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/libc/usr/lib/libstdc++.so.6.0.29-gdb.py
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/libc/usr/lib/libstdc++.so.6.0.29
./external-toolchain-dir/arm-gnu-toolchain-11.3.rel1-x86_64-arm-none-linux-gnueabihf/arm-none-linux-gnueabihf/libc/usr/lib/libstdc++.so

However, x86 has a different version of the libstdc++.so.

user@ip:/usr/lib$ !find
find . -name libstdc++.so*
./i386-linux-gnu/libstdc++.so.6
./i386-linux-gnu/libstdc++.so.6.0.30
./gcc/x86_64-linux-gnu/11/32/libstdc++.so
./gcc/x86_64-linux-gnu/11/x32/libstdc++.so
./gcc/x86_64-linux-gnu/11/libstdc++.so
./x86_64-linux-gnu/libstdc++.so.6
./x86_64-linux-gnu/libstdc++.so.6.0.30
./gcc-cross/arm-linux-gnueabihf/11/libstdc++.so

[SGaist]

Before diving deeper in that stuff, you wrote that you can build Qt without issue when webengine is disabled. What about building Qt like that and then manually you try to build WebEngine and PDF ?

[Vidya H]

How can I build WebEngine and PDF manually? Could you please guide me? I am working on this for the first time.

[SGaist]

Since Qt 6 uses cmake you can follow the same principle as other cmake projects.

Create a build folder and then use the qt-cmake wrapper that was generated as part of your build to configure then build the projects.

[Vidya H]

I am using Qt5. I have my project requirement to use Qt5.15.7 version only.

[SGaist]

Then use qmake. The rest is the same, create an out of source build folder, go into it, use the full path to your Qt cmake executable and pass it the path to the WebEngine folder.

[Vidya H]

I have a out of source build folder. I am currently trying to generate the qmake command to compile the application code. There is no Cmake as I am using Qt5. When i use the cmd ~/tqtc-qt5/configure --verbose -platform linux-g++ -xplatform linux-arm-gnueabihf-g++ -device-option CROSS_COMPILE=/usr/bin/arm-linux-gnueabihf- -sysroot /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi -prefix /home/user/qt5-build -commercial -confirm-license -release -gui -widgets -no-dbus -opengl -linuxfb -sql-sqlite -nomake examples -nomake tests -tslib, there are no errors. However, when I use the command ~/tqtc-qt5/configure --verbose -platform linux-g++ -xplatform linux-arm-gnueabihf-g++ -device-option CROSS_COMPILE=/usr/bin/arm-linux-gnueabihf- -sysroot /home/user/ti-processor-sdk-linux-am335x-evm-09.01.00.001/linux-devkit/sysroots/armv7at2hf-neon-oe-linux-gnueabi -prefix /home/user/qt5-build -commercial -confirm-license -release -gui -widgets -no-dbus -opengl -linuxfb -sql-sqlite -nomake examples -nomake tests -webengine-printing-and-pdf -tslib, I am getting errors. The only difference in the commands is the parameter -webengine-printing-and-pdf.

[SGaist]

What I suggested:

1. build Qt without the stuff that's breaking
2. create another folder just for WebEngine
3. from that folder call your freshly built qmake and point it to the source of the WebEngine module
4. build

[Vidya H]

I will try that. Thank you.