If a --python option is used to specify the Python to use in the #!
line also use this as the executable in the bundle.
diff --git a/Lib/plat-mac/bundlebuilder.py b/Lib/plat-mac/bundlebuilder.py
index 554b0f1..9c79e30 100755
--- a/Lib/plat-mac/bundlebuilder.py
+++ b/Lib/plat-mac/bundlebuilder.py
@@ -405,7 +405,10 @@
         if self.executable is None:
             if not self.standalone and not isFramework():
                 self.symlink_exec = 1
-            self.executable = sys.executable
+            if self.python:
+                self.executable = self.python
+            else:
+                self.executable = sys.executable
 
         if self.nibname:
             self.plist.NSMainNibFile = self.nibname