Could not load the Qt platform plugin "xcb" in "" even though it was found?

[A Former User]

This post is deleted!

[A Former User]

@JKSH Thank you for the suggestions. I stumbled upon a different forum post which linked the files accordingly for Debian:

sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0.0
sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0
sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1

Doing this seems to have solved the problem and the project runs successfully. The only concern is if this is safe long-term or in the event of deployment?

[JKSH]

Hi @StarkTech, and welcome!

Go to <Qt>/plugins/platforms/ and run ldd libqxcb.so. See what libraries are missing.

[A Former User]

Hi @JKSH and Thank you for the reply!

Running "ldd libqxcb.so" yielded the following:

@debian:/opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms# ldd libqxcb.so
        linux-vdso.so.1 (0x00007fff701f3000)
        libQt6XcbQpa.so.6 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libQt6XcbQpa.so.6 (0x00007fe39144e000)
        libxkbcommon-x11.so.0 => /lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007fe391428000)
        libxkbcommon.so.0 => /lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007fe3913e6000)
        libxcb-icccm.so.4 => /lib/x86_64-linux-gnu/libxcb-icccm.so.4 (0x00007fe3913df000)
        libxcb-image.so.0 => /lib/x86_64-linux-gnu/libxcb-image.so.0 (0x00007fe3911da000)
        libxcb-keysyms.so.1 => /lib/x86_64-linux-gnu/libxcb-keysyms.so.1 (0x00007fe390fd7000)
        libxcb-randr.so.0 => /lib/x86_64-linux-gnu/libxcb-randr.so.0 (0x00007fe390fc3000)
        libxcb-render-util.so.0 => /lib/x86_64-linux-gnu/libxcb-render-util.so.0 (0x00007fe390dbf000)
        libxcb-shm.so.0 => /lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fe390dba000)
        libxcb-sync.so.1 => /lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007fe390db0000)
        libxcb-xfixes.so.0 => /lib/x86_64-linux-gnu/libxcb-xfixes.so.0 (0x00007fe390da6000)
        libxcb-render.so.0 => /lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fe390d97000)
        libxcb-shape.so.0 => /lib/x86_64-linux-gnu/libxcb-shape.so.0 (0x00007fe390d90000)
        libxcb-xkb.so.1 => /lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007fe390d72000)
        libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fe390d48000)
        libQt6OpenGL.so.6 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libQt6OpenGL.so.6 (0x00007fe390ca7000)
        libQt6Gui.so.6 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libQt6Gui.so.6 (0x00007fe390352000)
        libGL.so.1 => /lib/x86_64-linux-gnu/libGL.so.1 (0x00007fe3902be000)
        libQt6Core.so.6 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libQt6Core.so.6 (0x00007fe38fc72000)
        libX11-xcb.so.1 => /lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007fe38fc6d000)
        libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007fe38fb2c000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fe38fb27000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fe38fb06000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fe38f982000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fe38f7fd000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fe38f7e3000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe38f623000)
        libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fe38f504000)
        libgthread-2.0.so.0 => /lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fe38f4ff000)
        libxcb-util.so.0 => /lib/x86_64-linux-gnu/libxcb-util.so.0 (0x00007fe38f2f6000)
        libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007fe38f0f2000)
        libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fe38eeec000)
        libEGL.so.1 => /lib/x86_64-linux-gnu/libEGL.so.1 (0x00007fe38eed7000)
        libfontconfig.so.1 => /lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007fe38ee91000)
        libQt6DBus.so.6 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libQt6DBus.so.6 (0x00007fe38edbd000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fe38ed9f000)
        libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007fe38ece3000)
        libGLX.so.0 => /lib/x86_64-linux-gnu/libGLX.so.0 (0x00007fe38ecaf000)
        libGLdispatch.so.0 => /lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007fe38ebf2000)
        libicui18n.so.56 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libicui18n.so.56 (0x00007fe38e757000)
        libicuuc.so.56 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libicuuc.so.56 (0x00007fe38e39f000)
        libicudata.so.56 => /opt/Qt/Tools/QtCreator/lib/Qt/plugins/platforms/./../../lib/libicudata.so.56 (0x00007fe38c9bc000)
        librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fe38c9b2000)
        /lib64/ld-linux-x86-64.so.2 (0x00007fe391502000)
        libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fe38c93e000)
        libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007fe38c924000)
        libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007fe38c8e5000)
        libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007fe38c8dc000)
        libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007fe38c889000)
        libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16 (0x00007fe38c850000)
        libXext.so.6 => /lib/x86_64-linux-gnu/libXext.so.6 (0x00007fe38c63e000)
        libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007fe38c59b000)
        liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fe38c573000)
        liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007fe38c554000)
        libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007fe38c436000)
        libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007fe38c413000)

[SGaist]

Hi and welcome to devnet,

Not Qt Creator's libraries, @JKSH asked you to check the one from the Qt version you use to build your application.

[A Former User]

@SGaist Hello and thank you for the reply as well. I believe this is the directory @JKSH was referring to? If this is wrong, please advice on where to locate this:

root@debian:/opt/Qt/5.15.2/gcc_64/plugins/platforms# ldd libqxcb.so
        linux-vdso.so.1 (0x00007ffce4be6000)
        libQt5XcbQpa.so.5 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libQt5XcbQpa.so.5 (0x00007f45032c4000)
        libfontconfig.so.1 => /lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f4503263000)
        libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f45031a7000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f4503189000)
        libQt5Gui.so.5 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libQt5Gui.so.5 (0x00007f4502858000)
        libQt5DBus.so.5 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libQt5DBus.so.5 (0x00007f45025cc000)
        libQt5Core.so.5 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libQt5Core.so.5 (0x00007f4501dd4000)
        libGL.so.1 => /lib/x86_64-linux-gnu/libGL.so.1 (0x00007f4501d40000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f4501d1f000)
        libX11-xcb.so.1 => /lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007f4501d1a000)
        libxcb-icccm.so.4 => /lib/x86_64-linux-gnu/libxcb-icccm.so.4 (0x00007f4501d13000)
        libxcb-image.so.0 => /lib/x86_64-linux-gnu/libxcb-image.so.0 (0x00007f4501b0e000)
        libxcb-shm.so.0 => /lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007f4501b07000)
        libxcb-util.so.1 => not found
        libxcb-keysyms.so.1 => /lib/x86_64-linux-gnu/libxcb-keysyms.so.1 (0x00007f4501904000)
        libxcb-randr.so.0 => /lib/x86_64-linux-gnu/libxcb-randr.so.0 (0x00007f45018f2000)
        libxcb-render-util.so.0 => /lib/x86_64-linux-gnu/libxcb-render-util.so.0 (0x00007f45016ee000)
        libxcb-render.so.0 => /lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007f45016df000)
        libxcb-shape.so.0 => /lib/x86_64-linux-gnu/libxcb-shape.so.0 (0x00007f45016d8000)
        libxcb-sync.so.1 => /lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007f45016ce000)
        libxcb-xfixes.so.0 => /lib/x86_64-linux-gnu/libxcb-xfixes.so.0 (0x00007f45016c4000)
        libxcb-xinerama.so.0 => /lib/x86_64-linux-gnu/libxcb-xinerama.so.0 (0x00007f45016bf000)
        libxcb-xkb.so.1 => /lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007f45016a1000)
        libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f4501677000)
        libXext.so.6 => /lib/x86_64-linux-gnu/libXext.so.6 (0x00007f4501463000)
        libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007f4501322000)
        libxkbcommon-x11.so.0 => /lib/x86_64-linux-gnu/libxkbcommon-x11.so.0 (0x00007f4501317000)
        libxkbcommon.so.0 => /lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f45012d5000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f45012d0000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f450114c000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f4500fc7000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f4500fad000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f4500ded000)
        libxcb-util.so.1 => not found
        libgthread-2.0.so.0 => /lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007f4500de8000)
        libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f4500cc9000)
        libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f4500c8a000)
        libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f4500c81000)
        libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f4500c48000)
        libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f4500bf5000)
        libicui18n.so.56 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libicui18n.so.56 (0x00007f450075c000)
        libicuuc.so.56 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libicuuc.so.56 (0x00007f45003a2000)
        libicudata.so.56 => /opt/Qt/5.15.2/gcc_64/plugins/platforms/./../../lib/libicudata.so.56 (0x00007f44fe9bf000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f4503823000)
        libGLX.so.0 => /lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f44fe98b000)
        libGLdispatch.so.0 => /lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007f44fe8ce000)
        libxcb-util.so.0 => /lib/x86_64-linux-gnu/libxcb-util.so.0 (0x00007f44fe6c7000)
        libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007f44fe4c1000)
        libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f44fe2bb000)
        libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f44fe247000)
        libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f44fe1a6000)
        libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f44fe18c000)
        librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f44fe180000)
        liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f44fe158000)
        liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f44fe139000)
        libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f44fe01b000)
        libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f44fdff8000)

[JKSH]

@StarkTech said in Could not load the Qt platform plugin "xcb" in "" even though it was found?:

libxcb-util.so.1 => not found

There's the issue. It needs libxcb-util.so.1

[A Former User]

@JKSH What command should be ran for this?

[JKSH]

@StarkTech said in Could not load the Qt platform plugin "xcb" in "" even though it was found?:

@JKSH What command should be ran for this?

I don't know. No official command exists because Debian 10.3 only has libxcb-util0 (https://packages.debian.org/buster/libxcb-util0 ) but Qt 5.15 wants libxcb-util1 (https://packages.debian.org/bullseye/libxcb-util1 )

Your options are:

• Find an unofficial way to install libxcb-util1 on Debian 10, OR
• Create a new VM with a different OS (Ubuntu 18.04, Ubuntu 20.04, or Debian 11) to use Qt 5.15, OR
• Uninstall your copy of Qt 5.15 and install the qt5-default package from the Debian 10 repository (https://packages.debian.org/buster/qt5-default ) -- Note: This gives you Qt 5.11, which is old and has reached end-of-life. I don't recommend this option for new projects.

[A Former User]

@JKSH Thank you for the suggestions. I stumbled upon a different forum post which linked the files accordingly for Debian:

sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0.0
sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1.0
sudo ln -fs /usr/lib/x86_64-linux-gnu/libxcb-util.so.0.0.0 /usr/lib/x86_64-linux-gnu/libxcb-util.so.1

Doing this seems to have solved the problem and the project runs successfully. The only concern is if this is safe long-term or in the event of deployment?

[JKSH]

@StarkTech said in Could not load the Qt platform plugin "xcb" in "" even though it was found?:

The only concern is if this is safe long-term or in the event of deployment?

I suppose it's safe as long as you ensure that you never install any other applications that will need the real libxcb-util.so.1.

You can do this on your own machine(s), but I wouldn't ask your project's end-users to do the same.