Fix c code in example and add c_code_cache_version.

doc/extending/fibby.txt

@@ -65,13 +65,19 @@ you should check the strides and alignment.
         Py_XDECREF(%(y)s);
         %(y)s = (PyArrayObject*)PyArray_FromArray(
                     %(x)s, 0, NPY_ARRAY_ENSURECOPY);
-        if (!(%y)s) %(fail)s;
-        dtype_%(y)s * y = (dtype_%(y)s*)%(y)s->data; 
-        dtype_%(x)s * x = (dtype_%(x)s*)%(x)s->data; 
-        for (int i = 2; i < %(x)s->dimensions[0]; ++i)
-          y[i] = y[i-1]*y[i-2] + x[i];
+        if (!%(y)s)
+            %(fail)s;
+        {//New scope needed to make compilation work
+            dtype_%(y)s * y = (dtype_%(y)s*)%(y)s->data;
+            dtype_%(x)s * x = (dtype_%(x)s*)%(x)s->data;
+            for (int i = 2; i < %(x)s->dimensions[0]; ++i)
+                y[i] = y[i-1]*y[i-2] + x[i];
+        }
       """ % locals()
 
+    def c_code_cache_version(self):
+      return (1,)
+
   fibby = Fibby()
 
 At a high level, the code fragment declares a class (``Fibby``) and then

theano/tests/test_tutorial.py

@@ -920,13 +920,19 @@ class T_fibby(unittest.TestCase):
                     Py_XDECREF(%(y)s);
                     %(y)s = (PyArrayObject*)PyArray_FromArray(
                             %(x)s, 0, NPY_ARRAY_ENSURECOPY);
-                    if (!(%y)s) %(fail)s;
-                    dtype_%(y)s * y = (dtype_%(y)s*)%(y)s->data;
-                    dtype_%(x)s * x = (dtype_%(x)s*)%(x)s->data;
-                    for (int i = 2; i < %(x)s->dimensions[0]; ++i)
-                        y[i] = y[i-1]*y[i-2] + x[i];
+                    if (!%(y)s)
+                        %(fail)s;
+                    {//New scope needed to make compilation work
+                        dtype_%(y)s * y = (dtype_%(y)s*)%(y)s->data;
+                        dtype_%(x)s * x = (dtype_%(x)s*)%(x)s->data;
+                        for (int i = 2; i < %(x)s->dimensions[0]; ++i)
+                            y[i] = y[i-1]*y[i-2] + x[i];
+                    }
                 """ % locals()
 
+            def c_code_cache_version(self):
+                return (1,)
+
         fibby = Fibby()
 
         from theano.tensor.opt import (get_scalar_constant_value,