Index: clang/cmake/caches/Fuchsia-stage2.cmake
===================================================================
--- clang/cmake/caches/Fuchsia-stage2.cmake
+++ clang/cmake/caches/Fuchsia-stage2.cmake
@@ -38,17 +38,28 @@
 set(LLVM_RUNTIME_TARGETS "default;x86_64-fuchsia;aarch64-fuchsia;x86_64-fuchsia-asan:x86_64-fuchsia;aarch64-fuchsia-asan:aarch64-fuchsia" CACHE STRING "")
 
 # Set the default target runtimes options.
-set(LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
-set(LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
-set(LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
-set(LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
-set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
-set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
-set(LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
-set(LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
-set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
-set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
-set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
+if(APPLE)
+  # Disable installing libc++, libc++abi or libunwind on Darwin, since Clang
+  # driver doesn't know how to use libraries that are part of the toolchain.
+  set(LIBUNWIND_INSTALL_HEADERS OFF CACHE BOOL "")
+  set(LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
+  set(LIBCXXABI_INSTALL_HEADERS OFF CACHE BOOL "")
+  set(LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
+  set(LIBCXX_INSTALL_HEADERS OFF CACHE BOOL "")
+  set(LIBCXX_INSTALL_LIBRARY OFF CACHE BOOL "")
+else()
+  set(LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
+  set(LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
+  set(LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
+  set(LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
+  set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
+  set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
+  set(LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
+  set(LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
+  set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
+  set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
+  set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
+endif()
 
 # Set the per-target runtimes options.
 foreach(target x86_64;aarch64)