The Qt 6.9 branch contains lupdate code that uses the deprecated LLVM FileManager::getFile() method, which was removed in LLVM 21. This causes compilation failures when building lupdate with LLVM 21.

native/6.9.3/sources/qttools-6.9.3/src/linguist/lupdate/cpp_clang.cpp
agent:2025/09/19 04:19:03 build.go:413: | In file included from /home/qt/work/build/build/tmp/work/x86_64-linux/qttools-native/6.9.3/sources/qttools-6.9.3/src/linguist/lupdate/cpp_clang.cpp:4:
agent:2025/09/19 04:19:03 build.go:413: | /home/qt/work/build/build/tmp/work/x86_64-linux/qttools-native/6.9.3/sources/qttools-6.9.3/src/linguist/lupdate/cpp_clang.h: In member function ‘clang::SourceLocation TranslationRelatedStore::callLocation(const clang::SourceManager&)’:
agent:2025/09/19 04:19:03 build.go:413: | /home/qt/work/build/build/tmp/work/x86_64-linux/qttools-native/6.9.3/sources/qttools-6.9.3/src/linguist/lupdate/cpp_clang.h:154:18: error: ‘class clang::FileManager’ has no member named ‘getFile’; did you mean ‘getFileRef’?
agent:2025/09/19 04:19:03 build.go:413: |   154 |                 .getFile(lupdateLocationFile.toStdString());
agent:2025/09/19 04:19:03 build.go:413: |       |                  ^~~~~~~
agent:2025/09/19 04:19:03 build.go:413: |       |                  getFileRef
agent:2025/09/19 04:19:03 build.go:413: | ninja: build stopped: subcommand failed.
agent:2025/09/19 04:19:03 build.go:413: | 
agent:2025/09/19 04:19:03 build.go:413: | WARNING: exit code 1 from a shell command.