fixed #4646 : distutils was choking on empty options arg in the setup function.
diff --git a/Lib/distutils/dist.py b/Lib/distutils/dist.py
index 9ad94fb..c15ca97 100644
--- a/Lib/distutils/dist.py
+++ b/Lib/distutils/dist.py
@@ -235,7 +235,7 @@
             # command options will override any supplied redundantly
             # through the general options dictionary.
             options = attrs.get('options')
-            if options:
+            if options is not None:
                 del attrs['options']
                 for (command, cmd_options) in options.items():
                     opt_dict = self.get_option_dict(command)