Index: cmake/Modules/HandleCompilerRT.cmake
===================================================================
--- cmake/Modules/HandleCompilerRT.cmake
+++ cmake/Modules/HandleCompilerRT.cmake
@@ -10,6 +10,7 @@
       OUTPUT_VARIABLE LIBRARY_FILE
   )
   string(STRIP "${LIBRARY_FILE}" LIBRARY_FILE)
+  file(TO_CMAKE_PATH "${LIBRARY_FILE}" LIBRARY_FILE)
   string(REPLACE "builtins" "${name}" LIBRARY_FILE "${LIBRARY_FILE}")
   if (NOT HAD_ERROR AND EXISTS "${LIBRARY_FILE}")
     message(STATUS "Found compiler-rt ${name} library: ${LIBRARY_FILE}")