unable to resolve host

gotchas.rst

@@ -8,4 +8,16 @@ VIM Arrow Keys Don't Work
 You may notice that by default, VIM's arrow keys don't work on your computer. To fix this, add the following to your ``~/.vimrc``::
 
     $ cat ~/.vimrc
-    set term=builtin_ansi
+    set term=builtin_ansi
+
+Sudo 'Unable to Resolve Host' Warning
+=====================================
+
+You may notice that every time you run ``sudo something``, your system complains that it cannot resolve it's own hostname, but then continues on anyway. To fix this annoyance, you need to add your system's hostname to ``/etc/hosts``::
+
+    $ cat /etc/hosts
+    127.0.0.1 localhost
+    127.0.0.1 nova
+    ...
+
+Here, my machine is called 'nova'.