Issue #10881: Fix test_site failures with OS X framework builds.
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 6000024..6314cfe 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -176,8 +176,9 @@
     if sys.platform == "darwin":
         framework = get_config_var("PYTHONFRAMEWORK")
         if framework:
-            return joinuser("~", "Library", framework, "%d.%d"%(
-                sys.version_info[:2]))
+            return env_base if env_base else \
+                               joinuser("~", "Library", framework, "%d.%d"
+                                            % (sys.version_info[:2]))
 
     return env_base if env_base else joinuser("~", ".local")