--- a/libinterp/corefcn/pt-jit.cc	Fri Mar 21 14:59:38 2014 -0400
+++ b/libinterp/corefcn/pt-jit.cc	Fri Mar 21 14:59:38 2014 -0400
@@ -230,13 +230,13 @@
 void
 jit_convert::visit_anon_fcn_handle (tree_anon_fcn_handle&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_anon_fcn_handle implementation");
 }
 
 void
 jit_convert::visit_argument_list (tree_argument_list&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_argument_list implementation");
 }
 
 void
@@ -337,25 +337,25 @@
 void
 jit_convert::visit_global_command (tree_global_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_global_command implemenation");
 }
 
 void
 jit_convert::visit_persistent_command (tree_persistent_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_persistent_command implementation");
 }
 
 void
 jit_convert::visit_decl_elt (tree_decl_elt&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_decl_elt implementation");
 }
 
 void
 jit_convert::visit_decl_init_list (tree_decl_init_list&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_decl_init_list implementation");
 }
 
 void
@@ -464,37 +464,37 @@
 void
 jit_convert::visit_complex_for_command (tree_complex_for_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_complex_for_command implementation");
 }
 
 void
 jit_convert::visit_octave_user_script (octave_user_script&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_octave_user_script implementation");
 }
 
 void
 jit_convert::visit_octave_user_function (octave_user_function&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_octave_user_function implementation");
 }
 
 void
 jit_convert::visit_octave_user_function_header (octave_user_function&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_octave_user_function_header implementation");
 }
 
 void
 jit_convert::visit_octave_user_function_trailer (octave_user_function&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_octave_user_function_trailer implementation");
 }
 
 void
 jit_convert::visit_function_def (tree_function_def&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_function_def implementation");
 }
 
 void
@@ -518,7 +518,7 @@
 void
 jit_convert::visit_if_clause (tree_if_clause&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_if_clause implementation");
 }
 
 void
@@ -630,25 +630,25 @@
 void
 jit_convert::visit_matrix (tree_matrix&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_matrix implementation");
 }
 
 void
 jit_convert::visit_cell (tree_cell&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_cell implementation");
 }
 
 void
 jit_convert::visit_multi_assignment (tree_multi_assignment&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_multi_assignment implementation");
 }
 
 void
 jit_convert::visit_no_op_command (tree_no_op_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_no_op_command implementation");
 }
 
 void
@@ -679,7 +679,7 @@
 void
 jit_convert::visit_fcn_handle (tree_fcn_handle&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_fcn_handle implementation");
 }
 
 void
@@ -691,7 +691,7 @@
 void
 jit_convert::visit_parameter_list (tree_parameter_list&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_parameter_list implementation");
 }
 
 void
@@ -727,13 +727,13 @@
 void
 jit_convert::visit_return_command (tree_return_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_return_command implementation");
 }
 
 void
 jit_convert::visit_return_list (tree_return_list&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_return_list implementation");
 }
 
 void
@@ -811,13 +811,13 @@
 void
 jit_convert::visit_switch_case (tree_switch_case&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_switch_case implementation");
 }
 
 void
 jit_convert::visit_switch_case_list (tree_switch_case_list&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_switch_case_list implementation");
 }
 
 void
@@ -945,13 +945,13 @@
 void
 jit_convert::visit_try_catch_command (tree_try_catch_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_try_catch_command implementation");
 }
 
 void
 jit_convert::visit_unwind_protect_command (tree_unwind_protect_command&)
 {
-  throw jit_fail_exception ();
+  throw jit_fail_exception ("No visit_unwind_protect_command implementation");
 }
 
 void