--- CMakeLists.txt.orig	2018-11-10 10:05:23.000000000 -0700
+++ CMakeLists.txt	2018-11-10 10:06:39.000000000 -0700
@@ -656,7 +656,7 @@
 endif()
 
 if(ENABLE_PYTHON)
-  find_package(PythonLibs)
+  find_package(PythonLibs __MACPORTS_PYTHON_VERSION__ REQUIRED)
   if(PYTHONLIBS_FOUND)
     list(APPEND EXTERNAL_LIBRARIES ${PYTHON_LIBRARIES})
     list(APPEND EXTERNAL_INCLUDES ${PYTHON_INCLUDE_DIRS})