You can see the error here: https://github.com/cristianadam/llvm-project/runs/443996527?check_suite_focus=true D:/a/llvm-project/llvm-project/llvm/tools/llvm-ar/llvm-ar.cpp: In function 'bool comparePaths(llvm::StringRef, llvm::StringRef)': D:/a/llvm-project/llvm-project/llvm/tools/llvm-ar/llvm-ar.cpp:524:10: error: 'CompareStringOrdinal' was not declared in this scope return CompareStringOrdinal(WPath1.data(), WPath1.size(), WPath2.data(), ^~~~~~~~~~~~~~~~~~~~ D:/a/llvm-project/llvm-project/llvm/tools/llvm-ar/llvm-ar.cpp:524:10: note: suggested alternative: 'CompareStringA' return CompareStringOrdinal(WPath1.data(), WPath1.size(), WPath2.data(), ^~~~~~~~~~~~~~~~~~~~ CompareStringA I have a build fix at: https://reviews.llvm.org/D74599
> I have a build fix at: https://reviews.llvm.org/D74599 That's now on master as 01f9abbb50b11dd26b9ccb7cb565cc955d2b9c74 and on 10.x as daae05af2a5d1170de6940569128dcf071db32ef. Thanks!