assist error diagnostics

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@35880 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/model/Queue.java

@@ -757,7 +757,8 @@ public class Queue extends ResourceController implements Saveable {
                         if(j.canTake(p.task))
                             candidates.add(j);
 
-                    Mapping m = loadBalancer.map(p.task, new MappingWorksheet(p, candidates));
+                    MappingWorksheet ws = new MappingWorksheet(p, candidates);
+                    Mapping m = loadBalancer.map(p.task, ws);
                     if (m == null)
                         // if we couldn't find the executor that fits,
                         // just leave it in the buildables list and