From aced1995fd13a3d01570ef2db5e82510f487fb7c Mon Sep 17 00:00:00 2001
From: Vladimir Prus <ghost@cs.msu.su>
Date: Thu, 9 Jan 2003 06:51:46 +0000
Subject: [PATCH] Add a diagnostic.

[SVN r16816]
---
 new/targets.jam      | 4 ++++
 v2/build/targets.jam | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/new/targets.jam b/new/targets.jam
index a909a9ca6..fa4f57c88 100644
--- a/new/targets.jam
+++ b/new/targets.jam
@@ -385,6 +385,10 @@ rule generate-dependencies ( properties * : project : extra-properties * )
         {
             local g = [ targets.generate $(p:G=) : $(project) 
               : $(properties) $(extra-properties) ] ;
+            if ! $(g) 
+            {
+                errors.error "cannot generate dependency " $(p) ;
+            }
             xproperties += $(p:G)$(g) [ $(g).use-requirements ] ;
         }
         else
diff --git a/v2/build/targets.jam b/v2/build/targets.jam
index a909a9ca6..fa4f57c88 100644
--- a/v2/build/targets.jam
+++ b/v2/build/targets.jam
@@ -385,6 +385,10 @@ rule generate-dependencies ( properties * : project : extra-properties * )
         {
             local g = [ targets.generate $(p:G=) : $(project) 
               : $(properties) $(extra-properties) ] ;
+            if ! $(g) 
+            {
+                errors.error "cannot generate dependency " $(p) ;
+            }
             xproperties += $(p:G)$(g) [ $(g).use-requirements ] ;
         }
         else