Build Qt6 from Source, xcb issue

nitingera

Re: [Built Qt6 from sources](problem with xcb plugin)

I have built Qt6.2 from source on CentOS 7.6 with gcc 10.2.1 (devtoolset-10) with the following configure options
./configure -developer-build -nomake tests -nomake examples -qt-zlib -qt-libpng -qt-libjpeg -opengl -bundled-xcb-xinput

The config summary is as follows

Building for: linux-g++ (x86_64, CPU features: mmx sse sse2)
Compiler: gcc 10.2.1
Build options:
  Mode ................................... debug
  Optimize debug build ................... no
  Fully optimize release builds (-O3) .... no
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++17
  Using ccache ........................... no
  Using new DTAGS ........................ yes
  Generating GDB index ................... no
  Relocatable ............................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    SSE .................................. SSE2 SSE3 SSSE3 SSE4.1 SSE4.2
    AVX .................................. AVX AVX2
    AVX512 ............................... F ER CD PF DQ BW VL IFMA VBMI
    Other x86 ............................ AES F16C RDRAND SHA
    Intrinsics without compiler architecture option  yes
  Sanitizers:
    Addresses ............................ no
    Threads .............................. no
    Memory ............................... no
    Fuzzer (instrumentation only) ........ no
    Undefined ............................ no
  Build parts ............................ libs tools
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  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 ...................... no
  Zstandard support ...................... no
  Thread support ......................... yes
Common build options:
  Linker can resolve circular dependencies  yes
Qt Core:
  backtrace .............................. yes
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... yes
  ICU .................................... yes
  Using system libb2 ..................... no
  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
  CLONE_PIDFD support in forkfd .......... yes
Qt Sql:
  SQL item models ........................ yes
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ yes
  OpenSSL 1.1 ............................ yes
  DTLS ................................... yes
  OCSP-stapling .......................... yes
  SCTP ................................... no
  Use system proxies ..................... yes
  GSSAPI ................................. yes
  Brotli Decompression Support ........... no
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ no
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... no
    PNG .................................. yes
      Using system libpng ................ no
  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 ................................. no
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... no
  INTEGRITY HID .......................... no
  mtdev .................................. no
  tslib .................................. no
  xkbcommon .............................. yes
  X11 specific:
    XLib ................................. yes
    XCB Xlib ............................. yes
    EGL on X11 ........................... yes
    xkbcommon-x11 ........................ yes
    xcb-sm ............................... no
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 ............................ yes
  LinuxFB ................................ yes
  VNC .................................... yes
  VK_KHR_display ......................... no
  QNX:
    lgmon ................................ no
    IMF .................................. no
  XCB:
    Using system-provided xcb-xinput ..... no
    GL integrations:
      GLX Plugin ......................... no
        XCB GLX .......................... no
      EGL-X11 Plugin ..................... no
  Windows:
    Direct 2D ............................ no
    Direct 2D 1.1 ........................ no
    DirectWrite .......................... no
    DirectWrite 3 ........................ no
Qt Widgets:
  GTK+ ................................... yes
  Styles ................................. Fusion Windows
Qt Testlib:
  Tester for item models ................. yes
Qt PrintSupport:
  CUPS ................................... yes
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite ................................. yes
    Using system provided SQLite ......... no
Core tools:
  qmake tool ............................. 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:
  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 3D:
  Assimp ................................. yes
  System Assimp .......................... no
  Use SSE2 instructions .................. yes
  Use AVX2 instructions .................. no
  Aspects:
    Render aspect ........................ yes
    Input aspect ......................... yes
    Logic aspect ......................... yes
    Animation aspect ..................... yes
    Extras aspect ........................ yes
Qt 3D APIs:
  Vulkan ................................. no
Qt 3D Renderers:
  OpenGL Renderer ........................ yes
  RHI Renderer ........................... yes
Qt3D Geometry Loaders:
  Autodesk FBX ........................... no
Qt 5 Compatibility Libraries:
  iconv .................................. no
Further Image Formats:
  JasPer ................................. no
  MNG .................................... yes
  TIFF ................................... yes
    Using system libtiff ................. yes
  WEBP ................................... yes
    Using system libwebp ................. no
Qt Quick Templates 2:
  Hover support .......................... yes
  Multi-touch support .................... yes
Qt Quick Controls 2:
  Styles ................................. Basic Fusion Imagine Material Universal macOS Windows
Qt Multimedia:
  ALSA ................................... no
  GStreamer 1.0 .......................... yes
  Video for Linux ........................ yes
  PulseAudio ............................. no
  MMRenderer ............................. no
  AVFoundation ........................... no
  Windows Media Foundation ............... no
Qt Charts Types:
  Area Chart ............................. yes
  Line Chart ............................. yes
  Spline Chart ........................... yes
  Scatter Chart .......................... yes
  Bar Chart .............................. yes
  Pie Chart .............................. yes
  Boxplot Chart .......................... yes
  Candlestick Chart ...................... yes
Qt Axis Types:
  DateTime Axis .......................... yes
Qt Tools:
  Qt Assistant ........................... yes
  QDoc ................................... no
  Clang-based lupdate parser ............. no
  Qt Designer ............................ yes
  Qt Distance Field Generator ............ yes
  Qt Linguist ............................ yes
  Mac Deployment Tool .................... no
  pixeltool .............................. yes
  qdbus .................................. yes
  Qt Attributions Scanner ................ yes
  qtdiag ................................. yes
  qtplugininfo ........................... yes
  Windows deployment tool ................ no
Serial Port:
  ntddmodm ............................... no
Qt Opcua:
  Open62541 .............................. yes
  Unified Automation C++ SDK ............. no
  Support for namespace 0 NodeId names ... yes
  Namespace 0 NodeIds generator .......... no
  Open62541 security support ............. yes
  Support for global discovery server .... yes
QtQuick3D:
  Assimp ................................. yes
  System Assimp .......................... no
Qt Remote Objects:
  High Availability Manager (ham) ........ no
Qt Scxml:
  ECMAScript data model for QtScxml ...... yes
Qt Sensors:
  sensorfw ............................... no
  sensorfw_enabled_with_cmake ............ no
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
  SerialPort Support ..................... yes
Qt Virtualkeyboard:
  Desktop integration .................... yes
  Built-in layouts ....................... yes
  Key navigation ......................... no
  Retro style as default ................. no
  Sensitive Debug ........................ no
  Cerence ................................ no
    Static Linking ....................... no
    Handwriting .......................... no
      Alphabetic ......................... no
      CJK ................................ no
    XT9 .................................. no
      XT9 Debug .......................... no
      XT9 9-key layouts .................. no
    Bundle resources ..................... no
      Handwriting ........................ no
      XT9 ................................ no
  Hunspell ............................... yes
    Using Hunspell copy from 3rdparty/ ... no
  OpenWnn ................................ yes
  MyScript ............................... no
Qt Wayland Drivers:
  EGL .................................... yes
  Raspberry Pi ........................... no
  XComposite EGL ......................... yes
  XComposite GLX ......................... yes
  DRM EGL ................................ yes
  libhybris EGL .......................... no
  Linux dma-buf server buffer integration  yes
  Vulkan-based server buffer integration . no
  Shm emulation server buffer integration  yes
Qt Wayland Client Shell Integrations:
  xdg-shell .............................. yes
  wayland_client_xdg_shell_v5 ............ no
  wayland_client_xdg_shell_v6 ............ no
  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 Wayland Drivers:
  EGL .................................... yes
  Raspberry Pi ........................... no
  XComposite EGL ......................... yes
  XComposite GLX ......................... yes
  DRM EGL ................................ yes
  libhybris EGL .......................... no
  Linux dma-buf server buffer integration  yes
  Vulkan-based server buffer integration . no
  Shm emulation server buffer integration  yes
Qt Wayland Client Shell Integrations:
  xdg-shell .............................. yes
  wayland_client_xdg_shell_v5 ............ no
  wayland_client_xdg_shell_v6 ............ no
  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
Build Features:
  Use system ninja ....................... yes
  Use system gn .......................... no
  Developer build ........................ yes
  Optional system libraries:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . no
    opus ................................. no
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... no
    glib ................................. yes
    zlib ................................. no
    minizip .............................. no
    libevent ............................. no
    protobuf ............................. no
    libxml2 and libxslt .................. no
    lcms2 ................................ no
    png .................................. no
    jpeg ................................. no
    harfbuzz ............................. no
    freetype ............................. yes
    libpci ............................... no

I am getting this error whenever I am trying to run any widgets application
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

There is not libqxcb.so present in qtbase/plugins/platforms
Do I need to specifically include any configuration option?

SGaist

Hi and welcome to devnet,

@nitingera said in Build Qt6 from Source, xcb issue:

xcb-sm ............................... no

I would say you are missing a development library here.

You can check the tests logs to see what has failed exactly.

JKSH

@SGaist said in Build Qt6 from Source, xcb issue:

@nitingera said in Build Qt6 from Source, xcb issue:

xcb-sm ............................... no

I would say you are missing a development library here.

I think so too.

Please ensure you've installed all the dependencies listed at https://doc.qt.io/qt-6/linux-requirements.html

Then, delete all the files generated through the configure/build process and try again.

nitingera

Thanks @SGaist and @JKSH
It worked after I installed the following packages

Xcb-util-keysyms-devel.x86_64
Xcb-util-renderutil-devel.x86_64
Xcb-util-image-devel.x86_64
Xcb-util-wm-devel.x86_64
Xcb-util-cursor-devel.x86_64
yum install libxcb libxcb-devel xcb-util xcb-util-devel

Listing the packages for future references :)

paulf

I have a similar problem to this (on RHEL 7.6 amd64) but without root access (and a very corporate IT that only does corporate IT things).

I've started building some dependencies that are too old/don't have dev packages installed (xcb, xcb-wm proto etc.).

Roughly what I've done is build these packages and then run configure with PKG_CONFIG_PATH pointing to their pkg-config directories.

However I still get

config.summary: xcb-sm ............................... no

I'm no expert in CMake. Can someone point out where this feature test gets logged?

paulf

configure -- --trace-expand seems to be what I need. Finding the failing test might be a bit of a challenge though as there is a huge amount of output.

So far I've built gperf, libxcb- x7 xorg- x4. If I have to build libxkbcommon then that will need meson and ninja.

QtWS: Super Early Bird Tickets Available!

Build Qt6 from Source, xcb issue