Use the new macresource module to open the accompanying resource file (if needed).
diff --git a/Mac/scripts/BuildApplication.py b/Mac/scripts/BuildApplication.py
index ee82b7a..a7c8f40 100644
--- a/Mac/scripts/BuildApplication.py
+++ b/Mac/scripts/BuildApplication.py
@@ -18,6 +18,7 @@
 from Carbon import Dlg
 import EasyDialogs
 import buildtools
+import macresource
 
 # Hmmm...
 MACFREEZEPATH = os.path.join(sys.prefix, ":Mac:Tools:macfreeze")
@@ -38,13 +39,7 @@
 PPC_ONLY=1
 
 
-try:
-	Res.GetResource('DITL', DLG_ID)
-except Res.Error:
-	Res.FSpOpenResFile("BuildApplication.rsrc", 1)
-else:
-	pass # we're an applet
-
+macresource.need('DITL', DLG_ID, "BuildApplication.rsrc")
 
 def main():
 	try: