How to run Qt 5.1.0 application on Debian

[Infinity]

Thanks for your answer.

A missing dependency

libxcb.so wasn't missing. I checked the dependencies using readelf and discovered that libQt5DBus.so is required by xcb. That one was missing, my applications are running now.

The paths can be set using qt.conf which seems a better choice than manipulating the system environment.

I will use qt.conf instead of /etc/environment to tell Qt where to look for plug-ins. But this works only for the plug-in libraries, not for the regular Qt libraries (correct?).
How tells the installer the system where to look for the Qt libraries (I found no qt.conf file)?

[wysota]

But this works only for the plug-in libraries, not for the regular Qt libraries (correct?).

Correct.

How tells the installer the system where to look for the Qt libraries (I found no qt.conf file)?

For Linux based systems you can set rpath or runpath so that the loader looks for libraries in a place set during compilation or you can use LD_LIBRARY_PATH to set the directory during application startup. Qt-based apps are by no means different than any other Linux application in this regard.

[Infinity]

I'm using the directory you suggested now and my applications are working. But I'm still interested so I'll check out rpath, runpath and LD_LIBRARY_PATH.