From b94a66797234144abe4e698ebd42e3ad9b641d3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Manuel=20de=20Morais=20Santos=20Costa?=
 <vsc@xato.(none)>
Date: Tue, 26 Jan 2010 12:37:10 +0000
Subject: [PATCH] fix uninited nb if booting from prolog (obs from nf).

---
 pl/debug.yap | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pl/debug.yap b/pl/debug.yap
index a43ae43bb..814dfe52b 100644
--- a/pl/debug.yap
+++ b/pl/debug.yap
@@ -145,6 +145,7 @@ nospyall.
 % debug mode -> debug flag = 1
 
 debug :-
+	( nb_getval('$spy_gn',L) -> true ; nb_setval('$spy_gn',1) ),
 	'$start_debugging'(on),
 	print_message(informational,debug(debug)).