$NetBSD$

--- tools/depbuild.cpp.orig	2007-04-16 15:40:03.000000000 +0000
+++ tools/depbuild.cpp
@@ -24,6 +24,7 @@ This program generates dependencies for 
 #include <iostream>
 #include <string>
 #include <cstdio>
+#include <unistd.h>
 using namespace std;
 
 #include "fileutil.h"
