os2 patch by Jeff Rush
diff --git a/Tools/freeze/freeze.py b/Tools/freeze/freeze.py
index 58bfecb..1f0356b 100755
--- a/Tools/freeze/freeze.py
+++ b/Tools/freeze/freeze.py
@@ -298,8 +298,9 @@
     cflags = defines + includes + ['$(OPT)']
     libs = [os.path.join(binlib, 'libpython$(VERSION).a')]
 
-    makevars = parsesetup.getmakevars(makefile_in)
     somevars = {}
+    if os.path.exists(makefile_in):
+        makevars = parsesetup.getmakevars(makefile_in)
     for key in makevars.keys():
         somevars[key] = makevars[key]