qtquick3d doc generation fails without system OpenXR

[   31s] + cmake --build build -j4 -t docs
[   31s] [1/28] Running syncqt.cpp for module: QtOpenXR
[   31s] [2/28] Running syncqt.cpp for module: QtQuick3DUtils
[   31s] [3/28] Running syncqt.cpp for module: QtQuick3DGlslParser
[   31s] [4/28] Running syncqt.cpp for module: QtQuick3DAssetImport
[   31s] [5/28] cd /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/src/3rdparty/openxr && /usr/libexec/qt6/syncqt @/home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/src/3rdparty/openxr/OpenXRPrivate_syncqt_all_args && /usr/bin/cmake -E copy_directory /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/src/3rdparty/openxr/include /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/include/QtOpenXR
[   31s] FAILED: src/3rdparty/openxr/CMakeFiles/OpenXRPrivate_sync_all_public_headers /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/src/3rdparty/openxr/CMakeFiles/OpenXRPrivate_sync_all_public_headers 
[   31s] cd /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/src/3rdparty/openxr && /usr/libexec/qt6/syncqt @/home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/src/3rdparty/openxr/OpenXRPrivate_syncqt_all_args && /usr/bin/cmake -E copy_directory /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/src/3rdparty/openxr/include /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/include/QtOpenXR

[   21s] + cmake -DCMAKE_BUILD_TYPE:STRING=RelWithDebInfo -DCMAKE_INSTALL_PREFIX:STRING=/usr -DCMAKE_MESSAGE_LOG_LEVEL:STRING=STATUS -S . -B build -GNinja -DQT_DISABLE_RPATH:BOOL=ON '-DCMAKE_C_FLAGS:STRING=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -ffat-lto-objects -g' '-DCMAKE_CXX_FLAGS:STRING=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -ffat-lto-objects -g' '-DCMAKE_EXE_LINKER_FLAGS:STRING=-Wl,--as-needed -Wl,--no-undefined' '-DCMAKE_MODULE_LINKER_FLAGS:STRING=-Wl,--as-needed -Wl,--no-undefined' '-DCMAKE_SHARED_LINKER_FLAGS:STRING=-Wl,--as-needed -Wl,--no-undefined' -DFEATURE_system_assimp=ON
[   21s] -- The CXX compiler identification is GNU 14.2.0
[   22s] -- The C compiler identification is GNU 14.2.0
[   22s] -- Detecting CXX compiler ABI info
[   22s] -- Detecting CXX compiler ABI info - done
[   22s] -- Check for working CXX compiler: /usr/bin/c++ - skipped
[   22s] -- Detecting CXX compile features
[   22s] -- Detecting CXX compile features - done
[   22s] -- Detecting C compiler ABI info
[   22s] -- Detecting C compiler ABI info - done
[   22s] -- Check for working C compiler: /usr/bin/cc - skipped
[   22s] -- Detecting C compile features
[   22s] -- Detecting C compile features - done
[   22s] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD
[   22s] -- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
[   22s] -- Found Threads: TRUE
[   22s] -- Performing Test HAVE_STDATOMIC
[   22s] -- Performing Test HAVE_STDATOMIC - Success
[   22s] -- Found WrapAtomic: TRUE
[   22s] -- Found OpenGL: /usr/lib64/libOpenGL.so
[   23s] -- Checking for feature set changes
[   23s] -- CMAKE_STRIP (original): /usr/bin/strip
[   23s] -- Performing Test strip --keep-section
[   23s] -- Performing Test strip --keep-section - TRUE
[   23s] -- CMAKE_STRIP (used by Qt): /home/abuild/rpmbuild/BUILD/qtquick3d-everywhere-src-6.8.0/build/libexec/qt6/qt-internal-strip
[   23s] -- Could NOT find WrapSystemOpenXR (missing: __openxr_found) (Required is at least version "1.0.29")
[   23s] -- Performing Test HAVE_DASH_UNDEFINED_SYMBOLS
[   23s] -- Performing Test HAVE_DASH_UNDEFINED_SYMBOLS - Success
[   23s] -- Performing Test HAVE_DASH_DASH_NO_UNDEFINED
[   23s] -- Performing Test HAVE_DASH_DASH_NO_UNDEFINED - Success
[   23s] -- Found ZLIB: /usr/lib64/libz.so (found version "1.3.1")
[   23s] -- Found WrapSystemZLIB: TRUE (found version "1.3.1")
[   23s] -- Using system ZLIB.
[   23s] -- Found WrapZLIB: TRUE (found version "1.3.1")
[   24s] -- Found WrapQuick3DAssimp: TRUE (Required is at least version "5.1.6")
[   24s] -- Performing Test Assimp
[   24s] -- Performing Test Assimp - Success
[   25s] -- Could NOT find WrapSystemOpenXR (missing: __openxr_found) (Required is at least version "1.0.29")
[   25s] -- Using Qt bundled OpenXR.
[   25s] -- Found WrapOpenXR: TRUE
[   25s] -- Tool 'Qt6::balsam' will be built from source.
[   25s] -- Tool 'Qt6::balsamui' will be built from source.
[   25s] -- Tool 'Qt6::meshdebug' will be built from source.
[   25s] -- Tool 'Qt6::shadergen' will be built from source.
[   25s] -- Tool 'Qt6::instancer' will be built from source.
[   25s] -- Tool 'Qt6::shapegen' will be built from source.
[   25s] -- Tool 'Qt6::materialeditor' will be built from source.
[   25s] -- Generated QtModulePlugins.cmake files for the following modules: Quick3DAssetImport
[   25s] -- The following packages have been found:
[   25s] 
[   25s]  * Qt6BuildInternals (required version >= 6.8.0)
[   25s]  * Qt6CoreTools (required version >= 6.8.0)
[   25s]  * Qt6Core (required version >= 6.8.0)
[   25s]  * Qt6Concurrent (required version >= 6.8.0)
[   25s]  * Qt6Network (required version >= 6.8.0)
[   25s]  * Qt6QuickTools (required version >= 6.8.0)
[   25s]  * OpenGL
[   25s]  * PkgConfig
[   25s]  * XKB (required version >= 0.5.0), XKB API common to servers and clients., <http://xkbcommon.org>
[   25s]  * Vulkan
[   25s]  * Qt6GuiTools (required version >= 6.8.0)
[   25s]  * Qt6DBusTools (required version >= 6.8.0)
[   25s]  * Qt6QmlTools (required version >= 6.8.0)
[   25s]  * WrapVulkanHeaders
[   25s]  * Qt6Quick (required version >= 6.8.0)
[   25s]  * Qt6WidgetsTools (required version >= 6.8.0)
[   25s]  * Qt6Widgets (required version >= 6.8.0)
[   25s]  * Qt6ShaderToolsTools (required version >= 6.8.0)
[   25s]  * Qt6ShaderTools (required version >= 6.8.0)
[   25s]  * Qt6QuickTimeline (required version >= 6.8.0)
[   25s]  * Qt6 (required version >= 6.8.0)
[   25s]  * ZLIB
[   25s]  * WrapSystemZLIB
[   25s]  * WrapZLIB
[   25s]  * assimp (required version >= 5.1.6)
[   25s]  * WrapQuick3DAssimp (required version >= 5.1.6)
[   25s]  * WrapOpenXR
[   25s] 
[   25s] -- The following OPTIONAL packages have not been found:
[   25s] 
[   25s]  * Qt6QmlCompilerPlusPrivate
[   25s]  * Qt6PacketProtocolPrivate (required version >= 6.8.0)
[   25s]  * OpenXR (required version >= 1.0.29)
[   25s]  * WrapSystemOpenXR (required version >= 1.0.29)