Hint on debuggin gunicorn

DEPLOYMENT.md

@@ -38,6 +38,7 @@ The Gunicorn config is the following:
         'args': (
             '--bind=127.0.0.1:8484',
             '--workers=5',
+            #'--preload',
             'coin.wsgi',
         ),
     }
@@ -46,6 +47,10 @@ Launching it is as simple as
 
     # service gunicorn start
 
+Hint: to debug gunicorn if it does not work, uncomment `--preload`
+and look at `/var/log/gunicorn/coin.log`.  Otherwise, you won't
+get any traceback.
+
 
 ## Nginx configuration