undefined symbols _main when building a shared lib on iOS with Qt::StateMachine

[thamht4190]

I'm migrating our project from Qt5.15.0 to Qt 6.3.0 on iOS. This is the linked issue I've got:

Undefined symbols for architecture arm64:
"_main", referenced from:
     user_main_trampoline() in libqios.a(qioseventdispatcher.mm.o)

After a while, I realized that the root cause is I'm building a shared lib which links to Qt::StateMachine while Qt::StateMachine depends on Qt::Gui and Qt::Gui requires a define main() method. I tried to remove this dependency in some cmake files inside <qt_install_path>/6.3.0/ios/lib/cmake/Qt6StateMachine/ folder, my build succeeds now.
I found out this is an external feature qeventtransition of Qt::StateMachine https://code.qt.io/cgit/qt/qtscxml.git/tree/src/statemachine/CMakeLists.txt?h=6.3.0#n34 then I hope that there is an official way to disable this feature then the dependency between StateMachine and Gui is no longer required.
Any help to bypass this problem? Thanks!