--- cmake/modules/pkg-config.cmake.orig	2017-01-29 10:50:35.000000000 +0900
+++ cmake/modules/pkg-config.cmake	2017-07-17 15:20:38.000000000 +0900
@@ -230,7 +230,7 @@
     "/System/Library/Frameworks/([^ ]*)\\.framework"
     "-framework \\1"
     link_flags
-    ${link_flags}
+    "${link_flags}"
     )
     #message("(frameworks) link_flags = ${link_flags}")
   endif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")