Add overriding on variable not found

calculate/lib/datavars.py

@@ -716,6 +716,9 @@ class DataVars:
                 varName = varObj.getVariableName()
                 self.allVars[varName] = (section,varObj)
 
+    def stubVariable(self,varname,*args,**kwargs):
+        raise DataVarsError(_("Variable %s not found")%varname)
+
     def loadVariable(self,varname):
         """
         Initialize variable 'varname' from fillObj and varObj.
@@ -741,7 +744,8 @@ class DataVars:
                 #setattr(newVar,"Get",self.Get)
                 self.loadVariables[varname] = newVar
             else:
-                raise DataVarsError(_("Variable %s not found")%varname)
+                self.loadVariables[varname] = \
+                    self.stubVariable(varname,parent=self,section="main")
 
     def defined(self,varName):
         """