Index: build/generator/swig/header_wrappers.py
===================================================================
--- build/generator/swig/header_wrappers.py	(revision 20217)
+++ build/generator/swig/header_wrappers.py	(working copy)
@@ -200,7 +200,8 @@
   if len(sys.argv) < 3:
     print """Usage: %s build.conf swig [ subversion/include/header_file.h ]
 Generates SWIG proxy wrappers around Subversion header files. If no header
-files are specified, generate wrappers for subversion/include/*.h. """
+files are specified, generate wrappers for subversion/include/*.h. """ % \
+    os.path.basename(sys.argv[0])
   else:
     gen = Generator(sys.argv[1], sys.argv[2])
     if len(sys.argv) > 3: