Index: TODO
===================================================================
diff -u -r7257200f41c3bd0d0309db6932e5788d860fa119 -rfe643dd6330cf3deb036335f20ce4113a2e2aee3
--- TODO	(.../TODO)	(revision 7257200f41c3bd0d0309db6932e5788d860fa119)
+++ TODO	(.../TODO)	(revision fe643dd6330cf3deb036335f20ce4113a2e2aee3)
@@ -3059,10 +3059,12 @@
 - extended regression test
 - added support for "class variable"
 - added tests for "variable" + multiplicity and "class variable"
+- provide error message, when method variable is a noop 
+  (e.g. no value provided and no accessor is wanted)
 
+
 TODO:
- - provide warning, when method variable is a noop 
-   (e.g. no value provided and no accessor is wanted)
+ - variable and incremental, test for user-defined types
  - should we change interface for default value in attribute? 
    probably not, same interface is used in methodparameters as well
  - Should we leave "variable" and "attribute" as it ist?
Index: library/nx/nx.tcl
===================================================================
diff -u -r7257200f41c3bd0d0309db6932e5788d860fa119 -rfe643dd6330cf3deb036335f20ce4113a2e2aee3
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 7257200f41c3bd0d0309db6932e5788d860fa119)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision fe643dd6330cf3deb036335f20ce4113a2e2aee3)
@@ -1646,6 +1646,8 @@
 	  set name $spec
 	}
 	set :$name $value
+      } else {
+	error "Variable definition for '$name' (without default and accessor) is useless"
       }
       return
     }
Index: tests/parameters.test
===================================================================
diff -u -r7257200f41c3bd0d0309db6932e5788d860fa119 -rfe643dd6330cf3deb036335f20ce4113a2e2aee3
--- tests/parameters.test	(.../parameters.test)	(revision 7257200f41c3bd0d0309db6932e5788d860fa119)
+++ tests/parameters.test	(.../parameters.test)	(revision fe643dd6330cf3deb036335f20ce4113a2e2aee3)
@@ -1861,8 +1861,10 @@
     ? [list [self] attribute -nocomplain [list xm2:int,1..n {1 2a 3}]] \
 	{invalid value in "1 2a 3": expected integer but got "2a"}
 
-    # more tests, e.g. multiplicity and user-defined type
-    # incremental, 
+    # useless definition
+    ? [list [self] variable dummy:int] {Variable definition for 'dummy' (without default and accessor) is useless}
+
+    # more tests, e.g. user-defined type and incremental
   }
 
   nx::Class create C {