--- utils/wvuid.cc.orig	2015-12-26 01:02:49.074068854 +0100
+++ utils/wvuid.cc	2015-12-26 01:03:12.700029921 +0100
@@ -33,6 +33,7 @@
 
 #else // not WIN32
 
+#include <unistd.h>
 
 WvString wv_username_from_uid(wvuid_t uid)
 {

.