Bug when running QT-based applications on Ubuntu

Compiling OTB with current develop and Superbuild works fine on ubuntu 18.04, however when running an application using QT with current otb and Superbuild, I run into :

qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: linuxfb, minimal, offscreen, vnc.

Aborted (core dumped)

with the current QT configure option and version 5.14, the library superbuild_install/plugins/platforms/libqxcb.so appears to be missing. It was built with previous versions of Qt. I think this is the cause of the bug.

adding -qt-xcb to the configure option of Qt might solve the problem (to be tested).

The bug can be reproduced on Linux by using the binary packages (recent develop, or 7.2 packages)

This is a blocking issue for the 7.2 release