make Validator.validate_(fgraph) print out information itself

theano/gof/toolbox.py

@@ -2,6 +2,7 @@ from __future__ import print_function
 from functools import partial
 import sys
 import time
+import inspect
 
 import theano
 from theano import config
@@ -200,7 +201,26 @@ class Validator(Feature):
 
     def validate_(self, fgraph):
         t0 = time.time()
-        ret = fgraph.execute_callbacks('validate')
+        try:
+            ret = fgraph.execute_callbacks('validate')
+        except Exception as e:
+            cf = inspect.currentframe()
+            uf = cf.f_back
+            uf_info = inspect.getframeinfo(uf)
+
+            # If the caller is replace_all_validate, just raise the
+            # exception. replace_all_validate will print out the
+            # verbose output.
+            # Or it has to be done here before raise.
+            if uf_info.function == 'replace_all_validate':
+                raise
+            else:
+                verbose = uf.f_locals['verbose']
+                r = uf.f_locals['r']
+                reason = uf_info.function
+                if verbose:
+                    print("validate failed on node %s.\n Reason: %s, %s" % (r, reason, e))
+                raise
         t1 = time.time()
         if fgraph.profile:
             fgraph.profile.validate_time += t1 - t0