@Ni.Sumi
I mean the compiler invocation, not the error (I saw the error in your first post). It should look something like this:

g++ -c -pipe -g -std=gnu++0x -Wall -W -D_REENTRANT -fPIC -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../myproject -I. -I../../../qt/qt-5.6/qtbase/include -I../../../qt/qt-5.6/qtbase/include/QtWidgets -I../../../qt/qt-5.6/qtbase/include/QtGui -I../../../qt/qt-5.6/qtbase/include/QtCore -I. -I../../../qt/qt-5.6/qtbase/mkspecs/linux-g++ -o somesource.o ../../myproject/somesource.cpp

/ I've taken it from g++, but you get the idea - the compile line, the call that compiles the offending source. /

Kind regards.

@Mark81 said:

SIGILL

That is an illegal instruction signal, which is pretty rare. Basically means the memory your program's residing in got corrupted somehow. So there's something very wrong. Check any callbacks, overwriting by mistake virtual tables and the such.

@luca yes you are right. :)
Just now I've tried to export the private key from the .p12 file with the openssl API. This key could be constructed into QSslKey object now. Thanks a lot.
But to configure in such a way is a little bit too complicated. Is there any class or method I can use, so that I can directly import the .p12 file into the QSslConfiguration object?