Index: libcxx/CMakeLists.txt
===================================================================
--- libcxx/CMakeLists.txt
+++ libcxx/CMakeLists.txt
@@ -401,7 +401,6 @@
   set(LIBCXX_HEADER_DIR  ${LLVM_BINARY_DIR})
 else()
   set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
-  set(LIBCXX_HEADER_DIR  ${CMAKE_BINARY_DIR})
 endif()
 
 file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
Index: libcxx/cmake/Modules/HandleLibCXXABI.cmake
===================================================================
--- libcxx/cmake/Modules/HandleLibCXXABI.cmake
+++ libcxx/cmake/Modules/HandleLibCXXABI.cmake
@@ -48,7 +48,7 @@
             COMMENT "Copying C++ ABI header ${fpath}...")
         list(APPEND abilib_headers "${dst}")
 
-        if (NOT LIBCXX_USING_INSTALLED_LLVM)
+        if (NOT LIBCXX_USING_INSTALLED_LLVM AND LIBCXX_HEADER_DIR)
           set(dst "${LIBCXX_HEADER_DIR}/include/c++/v1/${dstdir}/${fpath}")
           add_custom_command(OUTPUT ${dst}
               DEPENDS ${src}
Index: libcxx/include/CMakeLists.txt
===================================================================
--- libcxx/include/CMakeLists.txt
+++ libcxx/include/CMakeLists.txt
@@ -205,7 +205,7 @@
     )
 endif()
 
-if(NOT LIBCXX_USING_INSTALLED_LLVM AND LLVM_BINARY_DIR)
+if(NOT LIBCXX_USING_INSTALLED_LLVM AND LIBCXX_HEADER_DIR)
   set(output_dir ${LIBCXX_HEADER_DIR}/include/c++/v1)
 
   set(out_files)