[llvm-dev] Cannot compile LLVM suite with clang+lld

[via llvm-dev]

I try to compile LLVM, clang, lld and libcxx together in one source
directory following the instructions on the website.
I'm running Arch Linux and already have LLVM, clang, lld and libcxx
installed (prebuilt against libstdc++). Now I want a "pure"
llvm toolchain.

The following options were used:
-DBOOTSTRAP_LLVM_ENABLE_LLD
-DCMAKE_C_COMPILER=clang
-DCMAKE_CXX_COMPILER=clang++
-DCMAKE_LINKER=lld
-DCMAKE_LINK_EXECUTABLE="/usr/bin/ld.lld"
-DCMAKE_AR="/usr/bin/llvm-ar"
-DCMAKE_AS="/usr/bin/llvm-as"
-DCLANG_DEFAULT_LINKER=lld
-DCLANG_DEFAULT_RTLIB=compiler-rt
-DCLANG_ENABLE_BOOTSTRAP=ON
-DLIBCXX_USE_COMPILER_RT=ON
-DLIBCXXABI_USE_COMPILER_RT=ON
-DLLVM_ENABLE_LLD=ON
-DLLVM_ENABLE_LIBCXX=ON

However, the build fails with (many of those error messages):

[1274/2712] Linking CXX shared library lib/libc++abi.so.1.0
FAILED: lib/libc++abi.so.1.
/usr/bin/ld.lld: error: undefined symbol: _Unwind_Resume
>>> referenced by ld-temp.o
>>>               lto.tmp:(__cxa_demangle)

Can anyone please tell me what I am doing wrong and how I can fix the
build?

Regards
Andreas