--- xhprof_lib/utils/callgraph_utils.php.orig	2009-06-01 19:52:32.000000000 +0200
+++ xhprof_lib/utils/callgraph_utils.php	2010-03-24 23:37:02.000000000 +0100
@@ -103,7 +103,7 @@
        2 => array("file", "/dev/null", "a")
        );
 
-  $cmd = " dot -T".$type;
+  $cmd = " @PREFIX@/bin/dot -T".$type;
 
   $process = proc_open($cmd, $descriptorspec, $pipes, "/tmp", array());