Qt5.3.1 app deployment on Linux troubles

[march]

Hello everyone. I have some troubles when I deploy my app into Linux-platform. Unless specifically the problem lies in the platforms and sqldivers plugins.
There'r the steps what I did:
I compiled my app in Linux-platform and it's run perfect via QtCreator.
Next I temporary renamed some folder in path to Qt environment to disable this environment.
Next I created a folder e.g. /home/user/bin and replaced my app file, my libs, needed Qt -libs.
Then I added in .bashrc file LD_LIBRARY_PATH variable:
.bashrc:
...
LD_LIBRARY_PATH=/home/usr/bin
export LD_LIBRARY_PATH

Next I run ldd ./myapp to check libraries needed. All libs present.
Then I copied platforms and sqldrivers folders to my app folder.
Finally my distribution looks like:
platforms
sqldrivers
myapp
libme.so.1
libQt5Core.so.5
libQt5Gui.so.5
...

platforms folder:
libqxcb.so
libqoffscreen.so
libqminimal.so
libqlinuxfb.so

sqldrivers folder:
libqsqlmysql.so
libqsqlite.so

And when I do ./myapp in bash I see:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers:
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins
This application failed to start because it could not find or load the Qt platform plugin "xcb"

Then I added QT_QPA_PLATFORM_PLUGIN_PATH=/home/user/bin/platforms. Error messages were changed:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers:
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins
QFontDatabase: Cannot find font directory /home/usr/Qt/qtbase/lib/fonts - is Qt installed correctly?

At the moment I do not know what to do.

[SGaist]

Hi,

All plugins (except platforms but you already did it right) should go in the plugins subfolder.

Then you should be good to go

[liuqin2013]

I have the same troubles ,and when I set the environment variables:LD_LIBRARY_PATH and QT_QPA_PLATFORM_PLUGIN_PATH,then running the app like this:./imagegesture –plugin EvdevTouch ,the error is still exists:
This application failed to start because it could not find or load the Qt platform plugin "xcb".
Reinstalling the application may fix this problem.

add the QT_DEBUG_PLUGINS=1 ,i see the error exists because of the libxcb.so'version is incompatibale .

but i have not seen why the parameter "-plugin EdevTouch" has not work but it works in the development enviroment.

My OS is Fedora20 and Qt is 5.3.1
thanks！

[SGaist]

You don't have the same problem. Your target OS doesn't provide a suitable libxcb version.

[march]

Thanks to all for help.I found the solution.

1. We must make visible our libQt5*.so libs and our own libs for runtime. There is 2 ways to do (As I founded):

• use LD_LIBRARY_PATH env variable;
• use chrpath utility (this I used).
  I downloaded chrpath utility and change RPATH variable in myapp file.
  $ chrpath -r . myapp
  This allows runtime to check libraries in same directory when our app located (this Windows-like behavior)
  Note. using chrpath -l myapp before changing we can see current RPATH value.

2. Copy standart Qt plugins (platforms, sqldrivers etc) to defined directories.

• in my case it was /usr/lib/kde4/plugins (I defined it using "$ export QT_DEBUG_PLUGINS=1" before running my app). It works but we need root permissions.
  I did another way.
  I add code to myapp main()-functions and recompile there (and rewrite RPATH var again)
  @int main(int argc, char** argv)
  {
  QStringList paths = QCoreApplication::libraryPaths();
  paths.append(".");
  paths.append("imageformats");
  paths.append("platforms");
  paths.append("sqldrivers");
  paths.append("fonts");
  QCoreApplication::setLibraryPaths(paths);

  QApplication a(argc, argv);
  ...
  }
  @
  That means that plugins loader see this subfolders in myapp folder and can find plugins standart libraries in this folders.

3. Solution for QFontDatabase error -
   3.1) Copy fonts folder from ../qt/lib to .../myappfolder
   3.2) Define a QT_QPA_FONTDIR var -
   in my case
   $ export QT_QPA_FONTDIR=/home/usr/myappfolder/fonts
   $ ./myapp
   Thats it.
   We can do a shell script like this:
   @#!/bin/sh
   appname=basename $0 | sed s,\.sh$,,

dirname=dirname $0
tmp="${dirname#?}"

if [ "${dirname%$tmp}" != "/" ]; then
dirname=$PWD/$dirname
fi

#LD_LIBRARY_PATH=$dirname
#export LD_LIBRARY_PATH

export QT_QPA_FONTDIR=$dirname/fonts

$dirname/$appname "$@"@

Finally myappfolder looks like:
@

• fonts folder
• platforms folder
• imageformats folder (also copied from qt-folder/plugins)
• sqldrivers folder
• myapp.sh
• myapp
• libmyown.so.1
• libQt5*.so.5
• ...
  @

[SGaist]

You should Never (™) copy libraries like that, you might end up overwriting your system's own copy of Qt.