error building clang

Hi,
I am new to clang. I downloaded llvm and clang and fired a build, and I get the following error: Is this a known issue? Do I need to download Diagnostic.h from somewhere else?

In file included from /llvm/llvm/tools/clang/lib/Basic/Diagnostic.cpp:16:
/llvm/llvm/tools/clang/lib/Basic/…/…/include/clang/Basic/Diagnostic.h:591: error: clang::DiagnosticsEngine::<anonymous enum> clang::DiagnosticsEngine::MaxArguments' is private /llvm/llvm/tools/clang/lib/Basic/../../include/clang/Basic/PartialDiagnostic.h:36: error: within this context /llvm/llvm/tools/clang/lib/Basic/../../include/clang/Basic/Diagnostic.h:621: error: clang::DiagnosticsEngine:: clang::DiagnosticsEngine::MaxFixItHints’ is private
/llvm/llvm/tools/clang/lib/Basic/…/…/include/clang/Basic/PartialDiagnostic.h:68: error: within this context
make[3]: *** [/llvm/build/tools/clang/lib/Basic/Debug+Asserts/Diagnostic.o] Error 1
make[3]: Leaving directory /llvm/build/tools/clang/lib/Basic' make[2]: *** [Basic/.makeall] Error 2 make[2]: Leaving directory /llvm/build/tools/clang/lib’
make[1]: *** [all] Error 1