With XCode 10.0 and Qt 5.9.6 my project file (pro) file is failed to be parsed by Qmake. Here is the error details:
 

Project ERROR: This mkspec requires Xcode 4.3 or later
09:54:56: The process "/Users/abehera/Qt/5.9.6/ios/bin/qmake" exited with code 3.
Error while building/deploying project IOSTest (kit: Qt 5.9.6 (ios))
When executing step "qmake"
 

If I comment out XCode version Check in default_pre.prf, then I my pro file is parsed but build fails. I also added a message to print XCode version and a test function in my .pro file. Attached are the screenshots and the test project.

Note: Qt 5.11.2 works fine with XCode 10.0. However, I need to use Qt 5.9.6 for my project to support minimum iOS version iOS 8.