Here are some porting tips, contributed to the Metapkg project.

<ol>
<li>
When including &lt;sys/mman.h&gt;, you need to include 
&lt;sys/types.h&gt; first.
(See <a 
href="http://mail.gnome.org/archives/gnome-print-list/2001-April/msg00001.html">this 
mailing list item from gnome.org</a>.)</li>

</ol>