Facing issues cross-building Qt-everywhere-src-5.13.1 for Beaglebone Black, throwing undefined reference error with libQt5SerialPort.so.5 -- failing build.

SGaist

Hi and welcome to devnet,

Are you sure you have the udev development package for the correct architecture ?

Yash_r

@SGaist , Thank you for responding back.

I am quite new to Qt and building or using it.

I am trying to setup a cross-compilation scenario on an ubuntu machine to deploy on to BeagleBone Black running "BeagleBoard.org Debian Buster LXQt Image 2022-01-01" image.
So, i am not sure which udev package should i be focusing on?

Would really appreciate if you could let me know which udev package do i need to have and for which architecture?

Host Machine:
OS: Ubuntu 20.04.4 LTS 64-bit
Processor: Intel core i5

SGaist

libudev-dev

As for the architecture, you are cross-compiling so the one for your target,

Yash_r

@SGaist
When i run 'sudo apt install libudev-dev', i get the following output:

libudev-dev is already the newest version (245.4-4ubuntu3.17).

which as far as i can understand is for 'ubuntu' and not the 'arm-linux-gnueabihf-' required for Beaglebone Black (don't know if that's correct!?).

Any suggestion on how to proceed to solve this error?

Thanks.

SGaist

The usual way is to use the device and install there all the build requirements and then sync things back to build the sysroot.

Yash_r

@SGaist
An 'apt search libudev' after logging into the beaglebone black via SSH gives the following output:

libudev-dev/unknown,now 241-7~deb10u8rcnee0~buster+20211022 armhf [installed]
  libudev development files

libudev1/unknown,now 241-7~deb10u8rcnee0~buster+20211022 armhf [installed]
  libudev shared library

I believe i have the required libudev installed on the BBB, and also synced back as sysroot (also confirmed by searching 'libudev'' in the sysroot folder in the files app in ubuntu which showed the libudev.so in ''sysroot/lib/arm-linux-gnueabihf') being used in ./configure step.

SGaist

Which version is it ?

Yash_r

@SGaist
When i run "pkg-config --modversion udev" (found from one of stackoverflow threads to know the version of udev), i get the output as ''241" (don't know if that's how getting the version works).

SGaist

Then there's something strange going on since it's version 183 that seems to be requested when linking.

Do you have several udev librairies around ?

Yash_r

@SGaist
This udev is supposed to be taken from the sysroot of the baeaglebone black, right?

I checked the same "pkg-config --modversion udev" and that returned the same '241'.

SGaist

Did you try to do a full clean build ?

Yash_r

@SGaist Yes i did, but that didn't help as well.
The same LIBUDEV error was prominent in a clean build as well.

If you have succesfully built Qt for cross-compilation to the Beaglebone black, would you be able to share a guide or something about the actual process and exact commands?

SGaist

Did you already saw this guide ?

Yash_r

@SGaist
The below log is for the ./configure step:

Creating qmake...
...........................................................................................Done.
Info: creating super cache file /home/yash/QT5121/qt-everywhere-src-5.12.1/.qmake.super
Info: creating cache file /home/yash/QT5121/qt-everywhere-src-5.12.1/.qmake.cache
Info: creating stash file /home/yash/QT5121/qt-everywhere-src-5.12.1/.qmake.stash

This is the Qt Open Source Edition.

You have already accepted the terms of the Open Source license.

Running configuration tests...
Checking for gold linker... yes
Checking for machine tuple... yes
Checking for valid makespec... yes
Checking for target architecture... arm
Checking for host architecture... x86_64
Checking for alloca() in alloca.h... yes
Checking for C++14 support... yes
Checking for C++1z support... no
Checking for C99 support... yes
Checking for C11 support... yes
Checking for pkg-config... no
Checking for D-Bus >= 1.2... no
Checking for new dtags support... yes
Checking for D-Bus >= 1.2 (host)... yes
Checking for udev... no
Checking for POSIX fallocate()... yes
Checking for precompiled header support... yes
Checking for RDRAND instruction... no
Checking for symbol visibility support... yes
Checking for -Bsymbolic-functions support... no
Checking for STL compatibility... yes
Checking for zlib... no
Checking for clock_gettime()... yes
Checking for POSIX monotonic clock... yes
Checking for C++11 <future>... yes
Checking for dlopen()... yes
Checking for eventfd... yes
Checking for futimens()... yes
Checking for getauxval()... yes
Checking for getentropy()... no
Checking for GLib... no
Checking for POSIX iconv... yes
Checking for ICU... no
Checking for inotify... yes
Checking for SysV IPC... yes
Checking for linkat()... yes
Checking for ppoll()... yes
Checking for renameat2()... no
Checking for slog2... no
Checking for statx() in libc... no
Checking for 64 bit atomics... yes
Checking for DoubleConversion... no
Checking for PCRE2... no
Checking for O_CLOEXEC... yes
Checking for C++11 <random>... yes
Checking for working std::atomic for function pointers... yes
Checking for OpenSSL Headers... no
Checking for getifaddrs()... yes
Checking for IPv6 ifname... yes
Checking for Linux AF_NETLINK sockets... yes
Checking for xkbcommon >= 0.5.0... no
Checking for KMS... no
Checking for OpenVG... no
Checking for evdev... yes
Checking for FreeType... no
Checking for GBM... no
Checking for LinuxFB... yes
Checking for mtdev... no
Checking for default QPA platform... eglfs
Checking for HarfBuzz... no
Checking for libjpeg... no
Checking for tslib... no
Checking for Vulkan... no
Checking for XLib... no
Checking for CUPS... no
Checking for DB2 (IBM)... no
Checking for InterBase... no
Checking for MySQL... no
Checking for OCI (Oracle)... no
Checking for ODBC... no
Checking for PostgreSQL... no
Checking for SQLite (version 2)... no
Checking for TDS (Sybase)... no
Checking for Socket CAN... yes
Checking for Socket CAN FD... yes
Checking for C++14 make_unique()... yes
Checking for Direct3D 12... no
Checking for SDL2... no
Checking for Assimp... no
Checking for Autodesk FBX... no
Checking for Wayland client library... no
Checking for Wayland EGL library... no
Checking for wayland-server... no
Checking for BlueZ... no
Checking for sensorfw... no
Checking for Gypsy... no
Checking for WinRT Geolocation API... no
Checking for ALSA... no
Checking for GStreamer 1.0... no
Checking for GStreamer 0.10... no
Checking for Video for Linux... yes
Checking for OpenAL... no
Checking for PulseAudio >= 0.9.10... no
Checking for libresourceqt5... no
Checking for libclang... no
Checking for alsa... no
Checking for embedded... yes
Checking for thumb instruction set... /home/yash/QT5121/qt-everywhere-src-5.12.1/qtwebengine/configure.pri:300: 'extractCFlag' is not a recognized replace function.
/home/yash/QT5121/qt-everywhere-src-5.12.1/qtwebengine/configure.pri:302: 'extractCFlag' is not a recognized replace function.
/home/yash/QT5121/qt-everywhere-src-5.12.1/qtwebengine/configure.pri:305: 'extractCFlag' is not a recognized replace function.
no
Checking for bison... yes
Checking for flex... yes
Checking for gperf... no
Checking for host pkg-config... /usr/bin/pkg-config
Checking for poppler-cpp... no
Checking for pulseaudio >= 0.9.10... no
Checking for python2... /usr/bin/python2
Checking for d-bus... no
Checking for fontconfig... no
Checking for glib-2.0 >= 2.32.0... no
Checking for glibc > 2.16... yes
Checking for jsoncpp... no
Checking for khr... no
Checking for libdrm... no
Checking for libevent... no
Checking for libvpx... no
Checking for libwebp, libwebpmux and libwebpdemux... no
Checking for libxml2 and libxslt... no
Checking for minizip... no
Checking for system ninja... no
Checking for nss >= 3.26... no
Checking for opus... no
Checking for protobuf... no
Checking for re2... no
Checking for snappy... no
Checking for x11... no
Checking for xcomposite... no
Checking for xcursor... no
Checking for xi... no
Checking for xrandr... no
Checking for xtst... no
Checking for host compiler... no
Done running configuration tests.

Configure summary:

Building on: linux-g++ (x86_64, CPU features: mmx sse sse2)
Building for: devices/linux-beagleboard-g++ (arm, CPU features: neon)
Target compiler: gcc 6.4.1
Configuration: cross_compile use_gold_linker compile_examples enable_new_dtags largefile neon precompile_header shared rpath release c++11 c++14 concurrent dbus no-pkg-config 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++14
  Using ccache ........................... no
  Using gold linker ...................... yes
  Using new DTAGS ........................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. yes
  Build parts ............................ libs
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 ....................... no
  udev ................................... no
  Using system zlib ...................... no
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... no
  iconv .................................. yes
  ICU .................................... no
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  Using system PCRE2 ..................... no
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  OpenSSL ................................ no
    Qt directly linked to OpenSSL ........ no
  OpenSSL 1.1 ............................ no
  DTLS ................................... no
  SCTP ................................... no
  Use system proxies ..................... yes
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ no
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ no
  Fontconfig ............................. no
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... no
    PNG .................................. yes
      Using system libpng ................ no
  EGL .................................... no
  OpenVG ................................. no
  OpenGL:
    Desktop OpenGL ....................... no
    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 .............................. no
  X11 specific:
    XLib ................................. no
    EGL on X11 ........................... no
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. no
  LinuxFB ................................ yes
  VNC .................................... yes
  Mir client ............................. no
Qt Sql:
  SQL item models ........................ yes
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... no
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
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
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 ................................... no
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 ................................... no
  GStreamer 1.0 .......................... no
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. no
  PulseAudio ............................. no
  Resource Policy (libresourceqt5) ....... no
  Windows Audio Services ................. no
  DirectShow ............................. no
  Windows Media Foundation ............... no
Qt Tools:
  QDoc ................................... no
Qt WebEngine:
  Embedded build ......................... yes
  Pepper Plugins ......................... no
  Printing and PDF ....................... no
  Proprietary Codecs ..................... no
  Spellchecker ........................... yes
  Native Spellchecker .................... no
  WebRTC ................................. no
  Use System Ninja ....................... no
  Geolocation ............................ yes
  WebChannel support ..................... yes
  Use v8 snapshot ........................ yes
  Kerberos Authentication ................ no
  Building v8 snapshot supported ......... no
  Use ALSA ............................... no
  Use PulseAudio ......................... no
  Optional system libraries used:
    re2 .................................. no
    icu .................................. no
    libwebp, libwebpmux and libwebpdemux . no
    opus ................................. no
    ffmpeg ............................... no
    libvpx ............................... no
    snappy ............................... no
    glib ................................. no
    zlib ................................. no
    minizip .............................. no
    libevent ............................. no
    jsoncpp .............................. no
    protobuf ............................. no
    libxml2 and libxslt .................. no
    lcms2 ................................ no
    png .................................. no
    JPEG ................................. no
    harfbuzz ............................. no
    freetype ............................. no
    x11 .................................. no
  Required system libraries:
    fontconfig ........................... no
    dbus ................................. no
    nss .................................. no
    khr .................................. no
    glibc ................................ yes
  Required system libraries for qpa-xcb:
    libdrm ............................... no
    xcomposite ........................... no
    xcursor .............................. no
    xi ................................... no
    xrandr ............................... no
    xtst ................................. no

Note: No wayland-egl support detected. Cross-toolkit compatibility disabled.

WARNING: Disabling pkg-config since PKG_CONFIG_LIBDIR is not set and
the host's .pc files would be used (even if you set PKG_CONFIG_PATH).
Set this variable to the directory that contains target .pc files
for pkg-config to function correctly when cross-compiling or
use -pkg-config to override this test.

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 from a package. On macOS you could use Homebrew's llvm package.
On Windows you need to set LLVM_INSTALL_DIR to the installation path.

WARNING: gperf is required to build QtWebEngine.

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

Qt is now configured for building. Just run 'make'.
Once everything is built, you must run 'make install'.
Qt will be installed into '/home/yash/QT5121/sysroot-glibc-linaro-2.23-2018.05-arm-linux-gnueabihf//home/yash/Qt5ForBBB'.

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

And the below is the end of the sudo make install command:

make[2]: Leaving directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qttranslations/translations'
make[1]: Leaving directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qttranslations'
cd qtdoc/ && ( test -e Makefile || /home/yash/QT5121/qt-everywhere-src-5.12.1/qtbase/bin/qmake -o Makefile /home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc/qtdoc.pro ) && make -f Makefile install
make[1]: Entering directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc'
cd doc/ && ( test -e Makefile || /home/yash/QT5121/qt-everywhere-src-5.12.1/qtbase/bin/qmake -o Makefile /home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc/doc/doc.pro ) && make -f Makefile install
make[2]: Entering directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc/doc'
make[2]: Nothing to be done for 'install'.
make[2]: Leaving directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc/doc'
make[1]: Leaving directory '/home/yash/QT5121/qt-everywhere-src-5.12.1/qtdoc'

And somehow, following that guide, i can now succesfully use Qt for development for Beaglebone Black (even though there are some issues).

PS: I believe i was facing the since i was using qtcreator with a latest version (and not the version equivalent to the qt-source that was built, as recommended in that guide).

Also, is there any recent guide to build a new qt-source with cross-compilation for beaglebone black?

Thanks.