Strange issue with QXcbIntegration: Cannot create platform OpenGL context, neither GLX or EGL are enabled

andy0206

Hi,

I have a QT Quick application running on a Raspberry Pi Zero (Buster), QT5.12.11 cross compiled on a Ubuntu 20.04 VM using the well published tutorials. All is OK when I launch the application from QT Creator or via a remote terminal console, e.g. Putty. I DO NOT get any issues, and the 3D graphics render OK (e.g. my transparency elements on widgets are all rendering OK). However when I start the application locally on the RPi I get:

QXcbIntegration: Cannot create platform OpenGL context, neither GLX or EGL are enabled failed to acquire GL context to resolve capabilities, using defaults..

And all of the widgets with any transparency do not render correctly, either completely transparent or a white overlay.

When I set up the toolchain I used this configuration:

./configure -release -opengl es2 -device linux-rasp-pi-g++ -device-option CROSS_COMPILE=~/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf- -sysroot ~/raspi/sysroot -opensource -confirm-license -skip qtwebengine -no-icu -make libs -prefix /usr/local/qt5pi -extprefix ~/raspi/qt5pi -hostprefix ~/raspi/qt5 -no-use-gold-linker -v -no-gbm

Note: I am not using Webkit - so I skipped the compilation because I got a warning which I could not resolve for RPI zero.

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

and this was the output:

Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++11
  Using ccache ........................... no
  Using gold linker ...................... no
  Using new DTAGS ........................ 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 ............................... yes
  Qt D-Bus directly linked to libdbus .... yes
  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
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ yes
  GLib ................................... yes
  iconv .................................. yes
  ICU .................................... no
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  Using system PCRE2 ..................... yes
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
  SCTP ................................... no
  Use system proxies ..................... yes
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
  EGL .................................... yes
  OpenVG ................................. yes
  OpenGL:
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ yes
    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
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 ...................... no
    EGLFS GBM ............................ no
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... yes
    EGLFS X11 ............................ no
  LinuxFB ................................ yes
  VNC .................................... yes
  Mir client ............................. no
  XCB:
    Using system-provided XCB libraries .. yes
    XCB XKB .............................. yes
    XCB XInput ........................... no
    Native painting (experimental) ....... yes
    GL integrations:
      GLX Plugin ......................... no
      EGL-X11 Plugin ..................... no
Qt Sql:
  SQL item models ........................ yes
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite2 ................................ yes
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... yes
Qt Testlib:
  Tester for item models ................. yes
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
Further Image Formats:
  JasPer ................................. no
  MNG .................................... yes
  TIFF ................................... yes
    Using system libtiff ................. yes
  WEBP ................................... yes
    Using system libwebp ................. no
Qt QML:
  QML network support .................... yes
  QML debugging and profiling support .... yes
  QML sequence object .................... yes
  QML list model ......................... yes
  QML XML http request ................... yes
  QML Locale ............................. 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 Scxml:
  ECMAScript data model for QtScxml ...... yes
Qt Gamepad:
  SDL2 ................................... yes
Qt 3D:
  Assimp ................................. yes
  System Assimp .......................... no
  Output Qt3D Job traces ................. 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
Qt 3D GeometryLoaders:
  Autodesk FBX ........................... no
Qt Wayland Client ........................ no
Qt Wayland Compositor .................... no
Qt Bluetooth:
  BlueZ .................................. no
  BlueZ Low Energy ....................... no
  Linux Crypto API ....................... no
  WinRT Bluetooth 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 . yes
  Geoservice plugins:
    OpenStreetMap ........................ yes
    HERE ................................. yes
    Esri ................................. yes
    Mapbox ............................... yes
    MapboxGL ............................. no
    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 Tools:
  QDoc ................................... yes

Note: Also available for Linux: linux-clang linux-icc

Qt is now configured for building. Just run 'make'.
Once everything is built, you must run 'make install'.
Qt will be installed into '/home/developer/raspi/qt5pi'.

Prior to reconfiguration, make sure you remove any leftovers from
the previous build.

Note: the following from above:

EGL .................................... yes
OpenVG ................................. yes
OpenGL:
  Desktop OpenGL ....................... no
  OpenGL ES 2.0 ........................ yes

EGLFS .................................. yes
EGLFS details:
  EGLFS OpenWFD ........................ no
  EGLFS i.Mx6 .......................... no
  EGLFS i.Mx6 Wayland .................. no
  EGLFS RCAR ........................... no
  EGLFS EGLDevice ...................... no
  EGLFS GBM ............................ no
  EGLFS VSP2 ........................... no
  EGLFS Mali ........................... no
  EGLFS Raspberry Pi ................... yes

Qt 3D Renderers:
OpenGL Renderer ........................ yes

Has anyone got any ideas on why this is happening?

Surely if OpenGL was not installed or compiled correctly it would not work irrespective of how the application is launched. Seems odd to me why it works when launched remotely then not when launch locally in the RPi!!

Any help appreciated.

UPDATE

If I launch the application locally on the RPI from the command line with sudo then I have no error.

SGaist

Hi,

Does your standard user have proper access to xorg ?
Is the server running ?

andy0206

Hi,

Thanks for posting.

Yes, X server is running.
What is the best way to check if the current user has access to xorg? and how do you add the user?

FYI I only have one user on the Pi as per out of box when installing raspbarian.

SGaist

If you can log into your RPi locally with the graphical user interface working it should already be a good sign.

andy0206

Thanks. Yes, its all generally Good in terms of the display when logged in as pi user. As described, the issue only manifests when the application is launched locally from the pi user profile. Starting the application remotely or within Qt Creator is all Good. For now I have created a launch application script elevated with sudo and the application runs fine.

SGaist

Can you run GLXGears ?

andy0206

Hi, Yes it glxgears works fine - low frame rate, but that's to be expected on a PiZero.

SGaist

Without sudo ?

andy0206

Yes, sorry

SGaist

@andy0206 said in Strange issue with QXcbIntegration: Cannot create platform OpenGL context, neither GLX or EGL are enabled:

EGL on X11

I wonder if your issue related to that.

Does running your application with sudo use X or the frame buffer directly ?

andy0206

Hi,

I’m not entirely sure how to check for that. The application is not doing anything special, just a QML app with some custom styled controls which has transparency. I am using QtCamera in the application though.

SGaist

You would need a build with EGL on X11 enabled.

andy0206

@SGaist Ok, thank you. I'll give it a go