Index: libcxx/src/CMakeLists.txt
===================================================================
--- libcxx/src/CMakeLists.txt
+++ libcxx/src/CMakeLists.txt
@@ -293,6 +293,9 @@
     else()
       set(MERGE_ARCHIVES_ABI_TARGET
         "${CMAKE_STATIC_LIBRARY_PREFIX}${LIBCXX_CXX_STATIC_ABI_LIBRARY}${CMAKE_STATIC_LIBRARY_SUFFIX}")
+      if (LIBCXX_CXX_ABI_LIBRARY_PATH)
+        set(MERGE_ARCHIVES_ABI_TARGET "${LIBCXX_CXX_ABI_LIBRARY_PATH}/${MERGE_ARCHIVES_ABI_TARGET}")
+      endif ()
     endif()
     if (APPLE)
       set(MERGE_ARCHIVES_LIBTOOL "--use-libtool" "--libtool" "${CMAKE_LIBTOOL}")
@@ -308,6 +311,7 @@
       "${MERGE_ARCHIVES_ABI_TARGET}"
       "${MERGE_ARCHIVES_SEARCH_PATHS}"
     WORKING_DIRECTORY ${LIBCXX_BUILD_DIR}
+    DEPENDS ${MERGE_ARCHIVES_ABI_TARGET}
     )
   endif()
 endif()
Index: libcxxabi/src/CMakeLists.txt
===================================================================
--- libcxxabi/src/CMakeLists.txt
+++ libcxxabi/src/CMakeLists.txt
@@ -302,6 +302,7 @@
         "$<TARGET_LINKER_FILE:cxxabi_static>"
         "$<TARGET_LINKER_FILE:unwind_static>"
       WORKING_DIRECTORY ${LIBCXXABI_BUILD_DIR}
+      DEPENDS unwind_static
     )
   endif()
 endif()