Require Qt 6.4 for QML because of the use of ComponentBehavior: Bound

Author: daschuer

CMakeLists.txt

@@ -402,14 +402,6 @@ endif()
 include(CMakeDependentOption)
 
 option(QT6 "Build with Qt6" ON)
-cmake_dependent_option(
-  QML
-  "Build with QML"
-  ON
-  "QT6"
-  OFF
-)
-
 if(QT6)
   set(QOPENGL ON CACHE INTERNAL "Forced ON because QT6=ON")
 else()
@@ -420,10 +412,6 @@ if(QOPENGL)
   add_compile_definitions(MIXXX_USE_QOPENGL)
 endif()
 
-if(QML)
-  add_compile_definitions(MIXXX_USE_QML)
-endif()
-
 if(VCPKG_TARGET_TRIPLET MATCHES "^wasm(32|64)-emscripten")
   message(STATUS "Targeting Emscripten (${VCPKG_TARGET_TRIPLET})")
   if(DEFINED ENV{EMSDK})
@@ -2367,6 +2355,19 @@ if(QT6)
   if(NOT Qt6_FOUND)
     fatal_error_missing_env()
   endif()
+
+  # We need Qt 6.4 for ComponentBehavior: Bound
+  cmake_dependent_option(
+    QML
+    "Build with QML"
+    ON
+    "Qt6_VERSION VERSION_GREATER_EQUAL 6.4"
+    OFF
+  )
+  if(QML)
+    add_compile_definitions(MIXXX_USE_QML)
+  endif()
+
   # qt_add_executable() is the recommended initial call for qt_finalize_target()
   # below that takes care of the correct object order in the resulting binary
   # According to https://doc.qt.io/qt-6/qt-finalize-target.html it is importand for