Pi 4 - QT 5 with Open CV 4.1 App - No GUI Display - Problem with GTK

Mighty M · wrote on 12 Feb 2020, 07:40

Hi,

I've got an app that runs fine when I run it from sudo. When I dont run it from sudo (when developing/debugging on QtCreator), no GUI appears, and I get the following errors :

(tryme:21572): GLib-GObject-WARNING **: 07:12:03.833: cannot register existing type 'GtkWidget'

(tryme:21572): GLib-GObject-CRITICAL **: 07:12:03.834: g_type_add_interface_static: assertion 'G_TYPE_IS_INSTANTIATABLE (instance_type)' failed

(tryme:21572): GLib-GObject-WARNING **: 07:12:03.834: cannot register existing type 'GtkBuildable'

(tryme:21572): GLib-GObject-CRITICAL **: 07:12:03.834: g_type_interface_add_prerequisite: assertion 'G_TYPE_IS_INTERFACE (interface_type)' failed

(tryme:21572): GLib-CRITICAL **: 07:12:03.834: g_once_init_leave: assertion 'result != 0' failed

(tryme:21572): GLib-GObject-CRITICAL **: 07:12:03.834: g_type_add_interface_static: assertion 'G_TYPE_IS_INSTANTIATABLE (instance_type)' failed

(tryme:21572): GLib-GObject-CRITICAL **: 07:12:03.834: g_type_register_static: assertion 'parent_type > 0' failed

All of my QT apps work fine, but as soon as I add opencv lib to the .pro and build and run (with no code changes), the GUI doesnt appear.

I add this to my .pro, run qmake, build and run :

LIBS += -L/usr/local/lib -lopencv_world

When I run the app and pause it the stack on Thread #1 :

syscall
g_cond_wait
g_once_init_enter
gtb_buildable_get_type
gtb_container_get_type

ldd on the APP :

ldd JustQT
linux-vdso.so.1 (0xbec1d000)
/usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0xb6f93000)
libopencv_world.so.4.1 => /usr/local/lib/libopencv_world.so.4.1 (0xb51cb000)
libQt5Widgets.so.5 => /usr/lib/arm-linux-gnueabihf/libQt5Widgets.so.5 (0xb4c63000)
libQt5Gui.so.5 => /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5 (0xb47e3000)
libQt5Core.so.5 => /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5 (0xb4369000)
libGLESv2.so.2 => /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2 (0xb434a000)
libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb4320000)
libatomic.so.1 => /usr/lib/arm-linux-gnueabihf/libatomic.so.1 (0xb4307000)
libstdc++.so.6 => /usr/lib/arm-linux-gnueabihf/libstdc++.so.6 (0xb41c0000)
libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0xb413e000)
libgcc_s.so.1 => /lib/arm-linux-gnueabihf/libgcc_s.so.1 (0xb4111000)
libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb3fc3000)
libdl.so.2 => /lib/arm-linux-gnueabihf/libdl.so.2 (0xb3fb0000)
librt.so.1 => /lib/arm-linux-gnueabihf/librt.so.1 (0xb3f99000)
libz.so.1 => /lib/arm-linux-gnueabihf/libz.so.1 (0xb3f6e000)
libjpeg.so.62 => /usr/lib/arm-linux-gnueabihf/libjpeg.so.62 (0xb3f29000)
libpng16.so.16 => /usr/lib/arm-linux-gnueabihf/libpng16.so.16 (0xb3eed000)
libtiff.so.5 => /usr/lib/arm-linux-gnueabihf/libtiff.so.5 (0xb3e6d000)
libjasper.so.1 => /usr/lib/arm-linux-gnueabihf/libjasper.so.1 (0xb3e11000)
libgtk-3.so.0 => /usr/lib/arm-linux-gnueabihf/libgtk-3.so.0 (0xb37fb000)
libgdk-3.so.0 => /usr/lib/arm-linux-gnueabihf/libgdk-3.so.0 (0xb3723000)
libpangocairo-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libpangocairo-1.0.so.0 (0xb3708000)
libpango-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libpango-1.0.so.0 (0xb36bb000)
libatk-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libatk-1.0.so.0 (0xb368d000)
libcairo-gobject.so.2 => /usr/lib/arm-linux-gnueabihf/libcairo-gobject.so.2 (0xb3676000)
libcairo.so.2 => /usr/lib/arm-linux-gnueabihf/libcairo.so.2 (0xb357d000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgdk_pixbuf-2.0.so.0 (0xb354b000)
libgio-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgio-2.0.so.0 (0xb33cf000)
libgobject-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgobject-2.0.so.0 (0xb3372000)
libglib-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libglib-2.0.so.0 (0xb3262000)
libgthread-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgthread-2.0.so.0 (0xb3250000)
libhdf5_serial.so.103 => /usr/lib/arm-linux-gnueabihf/libhdf5_serial.so.103 (0xb2e54000)
libsz.so.2 => /usr/lib/arm-linux-gnueabihf/libsz.so.2 (0xb2e41000)
libfreetype.so.6 => /usr/lib/arm-linux-gnueabihf/libfreetype.so.6 (0xb2d9e000)
libharfbuzz.so.0 => /usr/lib/arm-linux-gnueabihf/libharfbuzz.so.0 (0xb2ca0000)
libavcodec.so.58 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libavcodec.so.58 (0xb1925000)
libavformat.so.58 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libavformat.so.58 (0xb16fc000)
libavutil.so.56 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libavutil.so.56 (0xb1673000)
libswscale.so.5 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libswscale.so.5 (0xb15f8000)
/lib/ld-linux-armhf.so.3 (0xb6fa8000)
libicui18n.so.63 => /usr/lib/arm-linux-gnueabihf/libicui18n.so.63 (0xb13aa000)
libicuuc.so.63 => /usr/lib/arm-linux-gnueabihf/libicuuc.so.63 (0xb1224000)
libpcre2-16.so.0 => /usr/lib/arm-linux-gnueabihf/libpcre2-16.so.0 (0xb11a8000)
libdouble-conversion.so.1 => /usr/lib/arm-linux-gnueabihf/libdouble-conversion.so.1 (0xb1184000)
libGLdispatch.so.0 => /usr/lib/arm-linux-gnueabihf/libGLdispatch.so.0 (0xb1105000)
libwebp.so.6 => /usr/lib/arm-linux-gnueabihf/libwebp.so.6 (0xb10a1000)
libzstd.so.1 => /usr/lib/arm-linux-gnueabihf/libzstd.so.1 (0xb1008000)
liblzma.so.5 => /lib/arm-linux-gnueabihf/liblzma.so.5 (0xb0fd7000)
libjbig.so.0 => /usr/lib/arm-linux-gnueabihf/libjbig.so.0 (0xb0fba000)
libgmodule-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgmodule-2.0.so.0 (0xb0fa6000)
libX11.so.6 => /usr/lib/arm-linux-gnueabihf/libX11.so.6 (0xb0e84000)
libXi.so.6 => /usr/lib/arm-linux-gnueabihf/libXi.so.6 (0xb0e66000)
libXcomposite.so.1 => /usr/lib/arm-linux-gnueabihf/libXcomposite.so.1 (0xb0e53000)
libXdamage.so.1 => /usr/lib/arm-linux-gnueabihf/libXdamage.so.1 (0xb0e40000)
libXfixes.so.3 => /usr/lib/arm-linux-gnueabihf/libXfixes.so.3 (0xb0e2b000)
libatk-bridge-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libatk-bridge-2.0.so.0 (0xb0df2000)
libxkbcommon.so.0 => /usr/lib/arm-linux-gnueabihf/libxkbcommon.so.0 (0xb0da9000)
libwayland-cursor.so.0 => /usr/lib/arm-linux-gnueabihf/libwayland-cursor.so.0 (0xb0d92000)
libwayland-egl.so.1 => /usr/lib/arm-linux-gnueabihf/libwayland-egl.so.1 (0xb0d80000)
libwayland-client.so.0 => /usr/lib/arm-linux-gnueabihf/libwayland-client.so.0 (0xb0d66000)
libepoxy.so.0 => /usr/lib/arm-linux-gnueabihf/libepoxy.so.0 (0xb0c70000)
libpangoft2-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libpangoft2-1.0.so.0 (0xb0c4e000)
libfontconfig.so.1 => /usr/lib/arm-linux-gnueabihf/libfontconfig.so.1 (0xb0c06000)
libXinerama.so.1 => /usr/lib/arm-linux-gnueabihf/libXinerama.so.1 (0xb0bf3000)
libXrandr.so.2 => /usr/lib/arm-linux-gnueabihf/libXrandr.so.2 (0xb0bda000)
libXcursor.so.1 => /usr/lib/arm-linux-gnueabihf/libXcursor.so.1 (0xb0bc1000)
libXext.so.6 => /usr/lib/arm-linux-gnueabihf/libXext.so.6 (0xb0ba2000)
libthai.so.0 => /usr/lib/arm-linux-gnueabihf/libthai.so.0 (0xb0b8a000)
libfribidi.so.0 => /usr/lib/arm-linux-gnueabihf/libfribidi.so.0 (0xb0b60000)
libpixman-1.so.0 => /usr/lib/arm-linux-gnueabihf/libpixman-1.so.0 (0xb0a85000)
libxcb-shm.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-shm.so.0 (0xb0a72000)
libxcb.so.1 => /usr/lib/arm-linux-gnueabihf/libxcb.so.1 (0xb0a43000)
libxcb-render.so.0 => /usr/lib/arm-linux-gnueabihf/libxcb-render.so.0 (0xb0a28000)
libXrender.so.1 => /usr/lib/arm-linux-gnueabihf/libXrender.so.1 (0xb0a0f000)
libmount.so.1 => /lib/arm-linux-gnueabihf/libmount.so.1 (0xb09ae000)
libselinux.so.1 => /lib/arm-linux-gnueabihf/libselinux.so.1 (0xb097c000)
libresolv.so.2 => /lib/arm-linux-gnueabihf/libresolv.so.2 (0xb0958000)
libffi.so.6 => /usr/lib/arm-linux-gnueabihf/libffi.so.6 (0xb0940000)
libpcre.so.3 => /lib/arm-linux-gnueabihf/libpcre.so.3 (0xb08c9000)
libaec.so.0 => /usr/lib/arm-linux-gnueabihf/libaec.so.0 (0xb08b1000)
libgraphite2.so.3 => /usr/lib/arm-linux-gnueabihf/libgraphite2.so.3 (0xb0880000)
libswresample.so.3 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libswresample.so.3 (0xb085a000)
libvpx.so.5 => /usr/lib/arm-linux-gnueabihf/libvpx.so.5 (0xb0757000)
libwebpmux.so.3 => /usr/lib/arm-linux-gnueabihf/libwebpmux.so.3 (0xb073d000)
libmmal_core.so => /opt/vc/lib/libmmal_core.so (0xb071f000)
libmmal_util.so => /opt/vc/lib/libmmal_util.so (0xb06ff000)
libmmal_vc_client.so => /opt/vc/lib/libmmal_vc_client.so (0xb06e4000)
libbcm_host.so => /opt/vc/lib/libbcm_host.so (0xb06ba000)
libvcsm.so => /opt/vc/lib/libvcsm.so (0xb06a0000)
librsvg-2.so.2 => /usr/lib/arm-linux-gnueabihf/librsvg-2.so.2 (0xb0292000)
libzvbi.so.0 => /usr/lib/arm-linux-gnueabihf/libzvbi.so.0 (0xb020f000)
libsnappy.so.1 => /usr/lib/arm-linux-gnueabihf/libsnappy.so.1 (0xb01f8000)
libaom.so.0 => /usr/lib/arm-linux-gnueabihf/libaom.so.0 (0xafefc000)
libcodec2.so.0.8.1 => /usr/lib/arm-linux-gnueabihf/libcodec2.so.0.8.1 (0xafe93000)
libgsm.so.1 => /usr/lib/arm-linux-gnueabihf/libgsm.so.1 (0xafe76000)
libmp3lame.so.0 => /usr/lib/arm-linux-gnueabihf/libmp3lame.so.0 (0xafdfa000)
libopenjp2.so.7 => /usr/lib/arm-linux-gnueabihf/libopenjp2.so.7 (0xafd9f000)
libopus.so.0 => /usr/lib/arm-linux-gnueabihf/libopus.so.0 (0xafd40000)
libshine.so.3 => /usr/lib/arm-linux-gnueabihf/libshine.so.3 (0xafd26000)
libspeex.so.1 => /usr/lib/arm-linux-gnueabihf/libspeex.so.1 (0xafcff000)
libtheoraenc.so.1 => /usr/lib/arm-linux-gnueabihf/libtheoraenc.so.1 (0xafcbe000)
libtheoradec.so.1 => /usr/lib/arm-linux-gnueabihf/libtheoradec.so.1 (0xafc96000)
libtwolame.so.0 => /usr/lib/arm-linux-gnueabihf/libtwolame.so.0 (0xafc66000)
libvorbis.so.0 => /usr/lib/arm-linux-gnueabihf/libvorbis.so.0 (0xafc2f000)
libvorbisenc.so.2 => /usr/lib/arm-linux-gnueabihf/libvorbisenc.so.2 (0xafb9d000)
libwavpack.so.1 => /usr/lib/arm-linux-gnueabihf/libwavpack.so.1 (0xafb67000)
libx264.so.155 => /usr/lib/arm-linux-gnueabihf/neon/vfp/libx264.so.155 (0xaf91b000)
libx265.so.165 => /usr/lib/arm-linux-gnueabihf/libx265.so.165 (0xaf661000)
libxvidcore.so.4 => /usr/lib/arm-linux-gnueabihf/libxvidcore.so.4 (0xaf571000)
libva.so.2 => /usr/lib/arm-linux-gnueabihf/libva.so.2 (0xaf542000)
libxml2.so.2 => /usr/lib/arm-linux-gnueabihf/libxml2.so.2 (0xaf3c5000)
libbz2.so.1.0 => /lib/arm-linux-gnueabihf/libbz2.so.1.0 (0xaf3a5000)
libgme.so.0 => /usr/lib/arm-linux-gnueabihf/libgme.so.0 (0xaf357000)
libopenmpt.so.0 => /usr/lib/arm-linux-gnueabihf/libopenmpt.so.0 (0xaf199000)
cut for brevity

I looked at each of the libs to see if there are any conflicts :

linux-vdso.so.1 (0xbee8b000)
/usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0xb517f000)
libatomic.so.1 => /usr/lib/arm-linux-gnueabihf/libatomic.so.1 (0xb514b000)
libdl.so.2 => /lib/arm-linux-gnueabihf/libdl.so.2 (0xb5138000)
libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb510e000)
librt.so.1 => /lib/arm-linux-gnueabihf/librt.so.1 (0xb50f7000)
libz.so.1 => /lib/arm-linux-gnueabihf/libz.so.1 (0xb50cc000)
libjpeg.so.62 => /usr/lib/arm-linux-gnueabihf/libjpeg.so.62 (0xb5087000)
libpng16.so.16 => /usr/lib/arm-linux-gnueabihf/libpng16.so.16 (0xb504b000)
libtiff.so.5 => /usr/lib/arm-linux-gnueabihf/libtiff.so.5 (0xb4fcb000)
libjasper.so.1 => /usr/lib/arm-linux-gnueabihf/libjasper.so.1 (0xb4f6f000)
libgtk-3.so.0 => /usr/lib/arm-linux-gnueabihf/libgtk-3.so.0 (0xb4959000)
libgdk-3.so.0 => /usr/lib/arm-linux-gnueabihf/libgdk-3.so.0 (0xb4881000)
libpangocairo-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libpangocairo-1.0.so.0 (0xb4866000)
libpango-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libpango-1.0.so.0 (0xb4819000)
libatk-1.0.so.0 => /usr/lib/arm-linux-gnueabihf/libatk-1.0.so.0 (0xb47eb000)
libcairo-gobject.so.2 => /usr/lib/arm-linux-gnueabihf/libcairo-gobject.so.2 (0xb47d4000)
libcairo.so.2 => /usr/lib/arm-linux-gnueabihf/libcairo.so.2 (0xb46db000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgdk_pixbuf-2.0.so.0 (0xb46a9000)
libgio-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgio-2.0.so.0 (0xb452d000)
libgobject-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgobject-2.0.so.0 (0xb44d0000)
libglib-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libglib-2.0.so.0 (0xb43c0000)
libgthread-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libgthread-2.0.so.0 (0xb43ae000)
libhdf5_serial.so.103 => /usr/lib/arm-linux-gnueabihf/libhdf5_serial.so.103 (0xb3fb2000)
libsz.so.2 => /usr/lib/arm-linux-gnueabihf/libsz.so.2 (0xb3f9f000)
cut for brevity

And QT 5 Gui lib

/QTExamples/build-JustQT-Desktop-Debug $ ldd /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5 | more
linux-vdso.so.1 (0xbedc4000)
/usr/lib/arm-linux-gnueabihf/libarmmem-${PLATFORM}.so => /usr/lib/arm-linux-gnueabihf/libarmmem-v7l.so (0xb6ac0000)
libQt5Core.so.5 => /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5 (0xb662b000)
libpthread.so.0 => /lib/arm-linux-gnueabihf/libpthread.so.0 (0xb6601000)
libGLESv2.so.2 => /usr/lib/arm-linux-gnueabihf/libGLESv2.so.2 (0xb65e2000)
libpng16.so.16 => /usr/lib/arm-linux-gnueabihf/libpng16.so.16 (0xb65a6000)
libharfbuzz.so.0 => /usr/lib/arm-linux-gnueabihf/libharfbuzz.so.0 (0xb64a8000)
libz.so.1 => /lib/arm-linux-gnueabihf/libz.so.1 (0xb647d000)
libstdc++.so.6 => /usr/lib/arm-linux-gnueabihf/libstdc++.so.6 (0xb6336000)
libm.so.6 => /lib/arm-linux-gnueabihf/libm.so.6 (0xb62b4000)
libgcc_s.so.1 => /lib/arm-linux-gnueabihf/libgcc_s.so.1 (0xb6287000)
libc.so.6 => /lib/arm-linux-gnueabihf/libc.so.6 (0xb6139000)
/lib/ld-linux-armhf.so.3 (0xb6f55000)
libatomic.so.1 => /usr/lib/arm-linux-gnueabihf/libatomic.so.1 (0xb6120000)
libicui18n.so.63 => /usr/lib/arm-linux-gnueabihf/libicui18n.so.63 (0xb5ed2000)
libicuuc.so.63 => /usr/lib/arm-linux-gnueabihf/libicuuc.so.63 (0xb5d4c000)
libpcre2-16.so.0 => /usr/lib/arm-linux-gnueabihf/libpcre2-16.so.0 (0xb5cd0000)
libdouble-conversion.so.1 => /usr/lib/arm-linux-gnueabihf/libdouble-conversion.so.1 (0xb5cac000)
libdl.so.2 => /lib/arm-linux-gnueabihf/libdl.so.2 (0xb5c99000)
libglib-2.0.so.0 => /usr/lib/arm-linux-gnueabihf/libglib-2.0.so.0 (0xb5b89000)
libGLdispatch.so.0 => /usr/lib/arm-linux-gnueabihf/libGLdispatch.so.0 (0xb5b0a000)
libfreetype.so.6 => /usr/lib/arm-linux-gnueabihf/libfreetype.so.6 (0xb5a67000)
libgraphite2.so.3 => /usr/lib/arm-linux-gnueabihf/libgraphite2.so.3 (0xb5a36000)
libicudata.so.63 => /usr/lib/arm-linux-gnueabihf/libicudata.so.63 (0xb4038000)
libpcre.so.3 => /lib/arm-linux-gnueabihf/libpcre.so.3 (0xb3fc1000)

Mighty M · wrote on 12 Feb 2020, 08:50

I have found the issue. There is a env var that sets the QT Style, and it was using gtk2. As can be seen from my lib dependencies, my app is linking in and using gtk3, so I changed the env var, and it works !

I thought about putting them in the environment folder (under etc), but for now I've put them in my .bashrc

export QT_QPA_PLATFORMTHEME=gtk3
export QT_STYLE_OVERRIDE=gtk3

Thanks
Marcus

nth.xx · wrote on 27 Aug 2020, 08:39

thank you so much, it's very useful for me @Mighty-M

saim · wrote on 13 Nov 2020, 16:41

@Mighty-M Unfortunately your solution did not work for me. Instead, I'have found another solution on the internet. Maybe it will help some other poor soul like me :)

edit qt5ct.conf file

sudo nano /etc/xdg/qt5ct/qt5ct.conf
replace style=gtk2 with style=gtk3
ctrl+x y ENTER