I may help you to know that what any xconfig does is to provide configuration parameters for software builds against that particular X server. Qt may need different parameters than does a program build some older/different interface.
The xconfig which may arrive in some basic form with X could work for many different software compile requirements, but Qt and some other software may provide their own version of this. Thus this is the reason why the xconfig you need is probably provided by Qt.
You might want to try Google Translate if you find language barriers. This works for English to Korean or Korean to English.
영어에서 한국어로 또는 한국어에서 영어로 작동하는 Google 번역을 사용해 볼 수 있습니다.