Add more explicit messagae to build_endpoint_map's check option

This will hopefully help developers know what to do if their patch fails
this verification.

Change-Id: I01fe9ca30295c6264affdbdb773b039a744289ea

1 files changed, 3 insertions, 2 deletions

diff --git a/network/endpoints/build_endpoint_map.py b/network/endpoints/build_endpoint_map.py
index 7e8088be..990cbabc 100755
--- a/network/endpoints/build_endpoint_map.py
+++ b/network/endpoints/build_endpoint_map.py
@@ -280,8 +280,9 @@ def main():
     try:
         if options.check:
             if not check_up_to_date(options.output_file, options.input_file):
-                print('EndpointMap template does not match input data',
-                      file=sys.stderr)
+                print('EndpointMap template does not match input data. Please '
+                      'run the build_endpoint_map.py tool to update the '
+                      'template.', file=sys.stderr)
                 sys.exit(2)
         else:
             build_endpoint_map(options.output_file, options.input_file)