background
When starting QT applications, we often encounter application startup failures and the qt platform plugin cannot be started, such as:
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: xcb.
Aborted (core dumped)
Troubleshooting methods
Turn on QT Plugin loading debugging switch
export QT_DEBUG_PLUGINS=1
Restart the application and you will get more detailed error information, as follows
QFactoryLoader::QFactoryLoader() checking directory path "/home/netease/working/hermes/pc_mac/build/bin/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so"
Found metadata in lib /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"xcb"
]
},
"archreq": 0,
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 331520
}
Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/netease/working/hermes/pc_mac/build/bin/platforms" ...
Cannot load library /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so: (libxcb-xinput.so.0: cannot open shared object file: No such file or directory)
QLibraryPrivate::loadPlugin failed on "/home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so" : "Cannot load library /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so: (libxcb-xinput.so.0: cannot open shared object file: No such file or directory)"
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: xcb.
Aborted (core dumped)
It can be seen that the root cause is that Cannot load library /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so: (libxcb-xinput.so.0: cannot open shared object file: No such file or directory)
it cannot be loaded libqxcb.soand the dependent dynamic library libxcb-xinput.so.0cannot be found. The ldd view is as follows:
[netease@netease-Precision-3630-Tower ~/working/hermes/pc_mac/build/bin]$ ldd /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/libqxcb.so
linux-vdso.so.1 (0x00007ffc3330b000)
libQt5XcbQpa.so.5 => /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/../../lib/libQt5XcbQpa.so.5 (0x00007fc35406c000)
libQt5Gui.so.5 => /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/../../lib/libQt5Gui.so.5 (0x00007fc353800000)
libQt5Core.so.5 => /home/netease/working/hermes/pc_mac/build/bin/plugins/platforms/../../lib/libQt5Core.so.5 (0x00007fc352b8f000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fc352806000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fc352415000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fc3521f6000)
libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007fc351ff4000)
libxcb-icccm.so.4 => /usr/lib/x86_64-linux-gnu/libxcb-icccm.so.4 (0x00007fc351def000)
libxcb-image.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-image.so.0 (0x00007fc351bea000)
libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fc3519e7000)
libxcb-keysyms.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-keysyms.so.1 (0x00007fc3517e4000)
libxcb-randr.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-randr.so.0 (0x00007fc3515d4000)
libxcb-render-util.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render-util.so.0 (0x00007fc3513d0000)
libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fc3511c3000)
libxcb-shape.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shape.so.0 (0x00007fc350fbf000)
libxcb-sync.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007fc350db8000)
libxcb-xfixes.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-xfixes.so.0 (0x00007fc350bb0000)
libxcb-xinerama.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-xinerama.so.0 (0x00007fc3509ad000)
libxcb-xinput.so.0 => not found
libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fc350675000)
libSM.so.6 => /usr/lib/x86_64-linux-gnu/libSM.so.6 (0x00007fc35046d000)
libICE.so.6 => /usr/lib/x86_64-linux-gnu/libICE.so.6 (0x00007fc350252000)
libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fc35002a000)
libxcb-xkb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-xkb.so.1 (0x00007fc34fe0e000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fc34fa70000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fc34f858000)
libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007fc34f5cc000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fc34f3c8000)
/lib64/ld-linux-x86-64.so.2 (0x00007fc35477b000)
libxcb-util.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-util.so.1 (0x00007fc34f1c2000)
libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007fc34efbb000)
libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007fc34eda6000)
libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fc34eba2000)
libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fc34e99c000)
libGLX.so.0 => /usr/lib/x86_64-linux-gnu/libGLX.so.0 (0x00007fc34e76b000)
libGLdispatch.so.0 => /usr/lib/x86_64-linux-gnu/libGLdispatch.so.0 (0x00007fc34e4b5000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fc34e2ad000)
indeed libxcb-xinput.so.0 => not found
Solution
Installing the correct third-party library can solve the problem
sudo apt install libxcb-xinput-dev