Only eglfs when cross-compiling QT static for Raspberry PI

Question

I have cross-compiled QT static for Raspberry PI using

./configure -opengl es2 -opensource -confirm-license -release -static \
            -prefix /usr/local/qt5static -hostprefix ~/raspi/qt5 -extprefix ~/raspi/qt5static \
            -device linux-rasp-pi-novc-g++ \
            -device-option CROSS_COMPILE=arm-raspbian-linux-gnueabihf- \
            -optimized-qmake -reduce-exports \
            -sysroot ~/raspi/sysroot \
            -make libs -make tools -no-use-gold-linker -v

where the 'novc' device is essentially the same as linux-rasp-pi-g++ but with no includes or libs from /opt/vc. When I run the program, it starts in full screen (because of eglfs), and when probed with export QT_DEBUG_PLUGINS=1 yields*

QFactoryLoader::QFactoryLoader() ignoring "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3" since plugins are disabled in static builds qt.qpa.plugin: Could not find the Qt platform plugin "android" in "" This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, eglfs.

It is fine that the factory loader fails, but why is there only eglfs, and where are there two of them? How can I make sure xcb is an option and that it is the default option?

*I use myapp -platform android since I know that Android is not in there. The dynamically linked QT from sudo apt install qt shows

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, xcb.

I would like that from my static compile. Here are my QPA backends (I do see eglfs for X11, and maybe that is what I have to trigger...)

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 ............................ no
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... no
    EGL on X11 ........................... yes
  LinuxFB ................................ yes
  VNC .................................... yes
  Mir client ............................. no
  X11:
    Using system-provided XCB libraries .. no
    EGL on X11 ........................... yes
    Xinput2 .............................. no
    XCB XKB .............................. yes
    XLib ................................. yes
    XCB render ........................... yes
    XCB GLX .............................. yes
    XCB Xlib ............................. yes
    Using system-provided xkbcommon ...... no
    Native painting (experimental) ....... no

My hello_plugin_import has this:

// This file is autogenerated by qmake. It imports static plugin classes for
// static plugins specified using QTPLUGIN and QT_PLUGIN_CLASS.<plugin> variables.
#include <QtPlugin>
Q_IMPORT_PLUGIN(QEglFSIntegrationPlugin)
Q_IMPORT_PLUGIN(QXcbEglIntegrationPlugin)
Q_IMPORT_PLUGIN(QXcbGlxIntegrationPlugin)
Q_IMPORT_PLUGIN(QGifPlugin)
Q_IMPORT_PLUGIN(QICNSPlugin)
Q_IMPORT_PLUGIN(QICOPlugin)
Q_IMPORT_PLUGIN(QJpegPlugin)
Q_IMPORT_PLUGIN(QTgaPlugin)
Q_IMPORT_PLUGIN(QTiffPlugin)
Q_IMPORT_PLUGIN(QWbmpPlugin)
Q_IMPORT_PLUGIN(QWebpPlugin)
Q_IMPORT_PLUGIN(QEglFSEmulatorIntegrationPlugin)
Q_IMPORT_PLUGIN(QEglFSKmsEglDeviceIntegrationPlugin)
Q_IMPORT_PLUGIN(QEglFSX11IntegrationPlugin)
Q_IMPORT_PLUGIN(QConnmanEnginePlugin)
Q_IMPORT_PLUGIN(QGenericEnginePlugin)
Q_IMPORT_PLUGIN(QNetworkManagerEnginePlugin)

Update. I noticed that I can install a bunch of libxcb packages into my sysroot. I think if I do this, I can get xcb to show up as platform option (or even default platform option??). But does this mess up my static compile? Will my customer also need to have all these libraries installed or will qmake do the right thing?

libglu1-mesa-dev is already the newest version (9.0.0-2.1).
libx11-xcb-dev is already the newest version (2:1.6.4-3).
libxcb-dri2-0-dev is already the newest version (1.12-1).
libxcb-dri2-0-dev set to manually installed.
libxcb-dri3-dev is already the newest version (1.12-1).
libxcb-dri3-dev set to manually installed.
libxcb-glx0-dev is already the newest version (1.12-1).
libxcb-present-dev is already the newest version (1.12-1).
libxcb-present-dev set to manually installed.
libxcb-randr0-dev is already the newest version (1.12-1).
libxcb-randr0-dev set to manually installed.
libxcb-render0-dev is already the newest version (1.12-1).
libxcb-render0-dev set to manually installed.
libxcb-shape0-dev is already the newest version (1.12-1).
libxcb-shape0-dev set to manually installed.
libxcb-sync-dev is already the newest version (1.12-1).
libxcb-sync-dev set to manually installed.
libxcb-xfixes0-dev is already the newest version (1.12-1).
libxcb-xfixes0-dev set to manually installed.
libxcb1-dev is already the newest version (1.12-1).
libxi-dev is already the newest version (2:1.7.9-1).
libxrender-dev is already the newest version (1:0.9.10-1).
The following additional packages will be installed:
  libxcb-composite0 libxcb-cursor0 libxcb-damage0 libxcb-dpms0 libxcb-ewmh2 libxcb-record0 libxcb-res0 libxcb-screensaver0 libxcb-xf86dri0 libxcb-xrm0 libxcb-xtest0
  libxcb-xv0 libxcb-xvmc0
The following NEW packages will be installed:
  libxcb-composite0 libxcb-composite0-dev libxcb-cursor-dev libxcb-cursor0 libxcb-damage0 libxcb-damage0-dev libxcb-dpms0 libxcb-dpms0-dev libxcb-ewmh-dev libxcb-ewmh2
  libxcb-icccm4-dev libxcb-image0-dev libxcb-keysyms1-dev libxcb-record0 libxcb-record0-dev libxcb-render-util0-dev libxcb-res0 libxcb-res0-dev libxcb-screensaver0
  libxcb-screensaver0-dev libxcb-shm0-dev libxcb-util0-dev libxcb-xf86dri0 libxcb-xf86dri0-dev libxcb-xinerama0-dev libxcb-xkb-dev libxcb-xrm-dev libxcb-xrm0 libxcb-xtest0
  libxcb-xtest0-dev libxcb-xv0 libxcb-xv0-dev libxcb-xvmc0 libxcb-xvmc0-dev

Answer 1

I believe that when you configure Qt with -static , you are baking the platform plugin into the build and you won't be able to swap between plugins later on. I'm not certain about this, but I've been down that road and wasn't able to get the qpa switching working, there was only ever one platform plugin listed. If there is a way, I'd be very interested to hear about it!

If I'm correct in this, then to use xcb instead of eglfs, you'll need to reconfigure Qt with the first line of your configure something like:

./configure -no-eglfs -qpa xcb -qt-xcb -opensource -confirm-license -release -static \

Good luck