Index: pylib/gyp/input.py
===================================================================
--- pylib/gyp/input.py	(revision 1107)
+++ pylib/gyp/input.py	(working copy)
@@ -666,7 +666,8 @@
             # that don't load quickly, this can be faster than
             # <!(python modulename param eters). Do this in |build_file_dir|.
             oldwd = os.getcwd()  # Python doesn't like os.open('.'): no fchdir.
-            os.chdir(build_file_dir)
+            if not build_file_dir is None:
+              os.chdir(build_file_dir)
 
             parsed_contents = shlex.split(contents)
             py_module = __import__(parsed_contents[0])