[Solved] Qt5.2.1 Platform issue on deployment, could not find xcb plugin. Linux
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Hi,
As a general rule, you should use the Qt 5 documentation, not the Qt 4 one. In this case though, the Linux deployment page hasn't changed in a long time.
Did you copy the script in http://qt-project.org/doc/qt-5/linux-deployment.html that sets LD_LIBRARY_PATH? (this variable tells your system where to find the libraries for your app)
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Yes, I did follow the Qt 5 documentation, I just linked the wrong one here.
I have copied the script and renamed it. I know LD_LIBRARY_PATH is set correctly as program doesn't complain about missing libraries when run from script (gives xcb error). Running direclty gives an error about a missing lib.
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[quote]
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This application failed to start because it could not find or load the Qt platform plugin "xcb".Available platform plugins are: xcb.
Reinstalling the application may fix this problem.
@
[/quote]I've encountered this unintuitive message before. In my case, Ubuntu found libqxcb.so but failed to load it because one of its dependencies was missing.Follow the quick-and-dirty method in this guide to identify the missing dependenc(ies): http://qt-project.org/wiki/Deploy_an_Application_on_Windows It's written for Windows but also works on Linux. Just replace *.dll with *.so
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Hi,
To add to JKSH, you can run ldd on your xcb plugin to see what libraries are linked and you'll also see if something is missing
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Thanks for your responses. Think I am having some progress, or am doing it totally wrong.
-So I orignally was using libqxcb.so from ~/Qt/5.2.1/gcc_64/plugins/platforms with no success. I thought perhaps this might be the incorrect library so I ran ldd on the source machine a picked out a version from where it was picking it's libs, /usr/lib/x86_64, this had more dependancies so I included them in the application directory.-
-Now I get a different error-
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~Desktop/graph-deploy/./mg_linux: symbol lookup error: ~Desktop/graph-deploy/./mg_linux: undefined symbol: _ZN19QAbstractScrollArea19setSizeAdjustPolicyENS_16SizeAdjustPolicyE
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-running cfilt identfies this as-
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QAbstractScrollArea::setSizeAdjustPolicy(QAbstractScrollArea::SizeAdjustPolicy)
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-Any ideas? Or have I gone the wrong way?--Also I compiled the original on Mint 15 and am trying to get it to run on Ubuntu 12.04. Will this be an issue?-
-I did notice that running-
@ldd -d -r@-on the original libqxcb I was using returned no missing libraries but many undefined symbol references.-
EDIT: ignore this rubbish!
Needed to solve the symbol errors for the file libqxcb.so from /Qt/5.2.1/gcc_64/plugins/platforms
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Thanks JKSH for putting me on the way to the solution!
[quote author="JKSH" date="1393037410"]
Follow the quick-and-dirty method in this guide to identify the missing dependenc(ies): http://qt-project.org/wiki/Deploy_an_Application_on_Windows It's written for Windows but also works on Linux. Just replace *.dll with *.so[/quote]Here is a Linux version of the above for those who may have a similar problem.
Firstly copy the required platform plugin libqxcb.so to a test directory ~/test_libs from /pathToQt/plugins/platforms in my case the pathToQt was ~/Qt/5.2.1/gcc_64/
Then copy all of the libraries from /pathToQt/lib to ~/test_libs
Set the LD_LIBRARY_PATH
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LD_LIBRARY_PATH=~/test_libs
export LD_LIBRARY_PATH
@Then run
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cd ~/test_libs
ldd -r -d libqxcb.so
@This should have no errors or undefined symbol messages.
Then you can delete libraries from ~/test_libs whilst rerunning ldd to work out the required libs, or delete all the libraries that ldd does not list from the directory ~/test_libs.
In my case libqxcb.so required the following libraries
libicudata.so.51
libicui18n.so.51
libicuuc.so.51
libQt5Core.so.5
libQt5DBus.so.5
libQt5Gui.so.5So I think my problem was that some incompatible libraries were found on the system so ldd didn't complain about them being missing.
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I'm glad that you've found a solution! Thank you for sharing your technique too.
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Hi
I am using CentOS 6.5 x86_64I created a GUI Application executable named "Graphitev1" using Qt5.2.1
It is a Widget based application.Below are dependency for my executable:
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ldd Graphitev1
linux-vdso.so.1 => (0x00007fff2d5ff000)libQt5PrintSupport.so.5 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libQt5PrintSupport.so.5 (0x00007f4dc6bef000) libQt5Widgets.so.5 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libQt5Widgets.so.5 (0x00007f4dc63a8000) libQt5Gui.so.5 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libQt5Gui.so.5 (0x00007f4dc5d22000) libQt5Core.so.5 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libQt5Core.so.5 (0x00007f4dc5654000) libGL.so.1 => /usr/lib64/libGL.so.1 (0x0000003195800000) libpthread.so.0 => /lib64/libpthread.so.0 (0x000000318a800000) libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x0000003196400000) libm.so.6 => /lib64/libm.so.6 (0x000000318b400000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x0000003195000000) libc.so.6 => /lib64/libc.so.6 (0x000000318a000000) libgobject-2.0.so.0 => /lib64/libgobject-2.0.so.0 (0x000000318c800000) libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x000000318b800000) libX11.so.6 => /usr/lib64/libX11.so.6 (0x000000318e000000) libicui18n.so.51 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libicui18n.so.51 (0x00007f4dc5226000) libicuuc.so.51 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libicuuc.so.51 (0x00007f4dc4ea0000) libdl.so.2 => /lib64/libdl.so.2 (0x000000318a400000) libgthread-2.0.so.0 => /lib64/libgthread-2.0.so.0 (0x000000318cc00000) librt.so.1 => /lib64/librt.so.1 (0x000000318ac00000) /lib64/ld-linux-x86-64.so.2 (0x0000003189c00000) libglapi.so.0 => /usr/lib64/libglapi.so.0 (0x0000003197000000) libXext.so.6 => /usr/lib64/libXext.so.6 (0x000000318e800000) libXdamage.so.1 => /usr/lib64/libXdamage.so.1 (0x0000003191400000) libXfixes.so.3 => /usr/lib64/libXfixes.so.3 (0x0000003192000000) libX11-xcb.so.1 => /usr/lib64/libX11-xcb.so.1 (0x000000318f000000) libxcb-glx.so.0 => /usr/lib64/libxcb-glx.so.0 (0x0000003196c00000) libxcb-dri2.so.0 => /usr/lib64/libxcb-dri2.so.0 (0x0000003195c00000) libxcb.so.1 => /usr/lib64/libxcb.so.1 (0x000000318dc00000) libXxf86vm.so.1 => /usr/lib64/libXxf86vm.so.1 (0x0000003196000000) libdrm.so.2 => /usr/lib64/libdrm.so.2 (0x0000003196800000) libselinux.so.1 => /lib64/libselinux.so.1 (0x000000318bc00000) libicudata.so.51 => /home/vedams/Qt5.2.1/5.2.1/gcc_64/lib/libicudata.so.51 (0x00007f4dc3752000)
libXau.so.6 => /usr/lib64/libXau.so.6 (0x000000318d800000)@
Now i am copying this executable "Graphitev1" with dependency in another CentOS 6.5 x86_64 machine and below is contents:
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ls -lh
-rwxrwxr-x. 1 vedams vedams 4.7M May 19 18:11 Graphitev1
lrwxrwxrwx. 1 vedams vedams 18 May 19 18:19 libicudata.so.51 -> libicudata.so.51.1
-rwxr-xr-x. 1 vedams vedams 22M May 19 18:11 libicudata.so.51.1
lrwxrwxrwx. 1 vedams vedams 18 May 19 18:19 libicui18n.so.51 -> libicui18n.so.51.1
-rwxr-xr-x. 1 vedams vedams 2.6M May 19 18:11 libicui18n.so.51.1
lrwxrwxrwx. 1 vedams vedams 16 May 19 18:18 libicuuc.so.51 -> libicuuc.so.51.1
-rwxr-xr-x. 1 vedams vedams 1.8M May 19 18:11 libicuuc.so.51.1
lrwxrwxrwx. 1 vedams vedams 19 May 19 18:18 libQt5Core.so.5 -> libQt5Core.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 4.8M May 19 18:11 libQt5Core.so.5.2.1
lrwxrwxrwx. 1 vedams vedams 19 May 19 18:17 libQt5DBus.so.5 -> libQt5DBus.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 523K May 19 18:11 libQt5DBus.so.5.2.1
lrwxrwxrwx. 1 vedams vedams 18 May 19 18:17 libQt5Gui.so.5 -> libQt5Gui.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 4.6M May 19 18:11 libQt5Gui.so.5.2.1
lrwxrwxrwx. 1 vedams vedams 27 May 19 18:16 libQt5PrintSupport.so.5 -> libQt5PrintSupport.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 412K May 19 18:11 libQt5PrintSupport.so.5.2.1
lrwxrwxrwx. 1 vedams vedams 22 May 19 18:12 libQt5Widgets.so.5 -> libQt5Widgets.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 6.3M May 19 18:11 libQt5Widgets.so.5.2.1
-rwxr-xr-x. 1 vedams vedams 1.4M May 19 18:11 libqxcb.so
@now i exported the LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PWD
now when i ran the application, i got the error
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This application failed to start because it could not find or load the Qt platform plugin "xcb".
Reinstalling the application may fix this problem.
Aborted (core dumped)
@Please tell me in simple manner , how to resolve this error
I m getting lost in above thread and following other links -
libqxcb.so needs to reside in a folder called platforms within the application source.
I found it very annoying when I had this error meassge to solve.
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Thanks a lot Ajp1989.Its working
But can yu please explain the reason behind thisAnd can yu give the standard procedure to pack applcation to deliver it to client.Currently for testing purpose i hardcoded lot of things.
By Target Machine and development machines are CentOS-6.5 x86_64
And i am developing a Desktop Widget based Application -
Hi, I also had problems before when deploying to Ubuntu machines. I wrote about it in 2 blog posts: "how to deploy":http://www.tripleboot.org/?p=138 (scroll down to Linux GCC...) and "why you need":http://www.tripleboot.org/?p=536 that platforms directory.
