Index: lldb/cmake/modules/LLDBStandalone.cmake
===================================================================
--- lldb/cmake/modules/LLDBStandalone.cmake
+++ lldb/cmake/modules/LLDBStandalone.cmake
@@ -14,7 +14,7 @@
 
   option(LLVM_INSTALL_TOOLCHAIN_ONLY "Only include toolchain files in the 'install' target." OFF)
 
-  set(LLDB_PATH_TO_LLVM_BUILD "" CACHE PATH "Path to LLVM build tree")
+  set(LLDB_PATH_TO_LLVM_BUILD "${LLVM_DIR}" CACHE PATH "Path to LLVM build tree")
   set(LLDB_PATH_TO_CLANG_BUILD "${LLDB_PATH_TO_LLVM_BUILD}" CACHE PATH "Path to Clang build tree")
 
   file(TO_CMAKE_PATH "${LLDB_PATH_TO_LLVM_BUILD}" LLDB_PATH_TO_LLVM_BUILD)