More informative error message when loading a graph_def which uses unknown ops.

Fixes #17014

PiperOrigin-RevId: 194472083

2 files changed, 33 insertions, 9 deletions

diff --git a/tensorflow/core/framework/op.cc b/tensorflow/core/framework/op.cc
index 5f68c59fe9..0873d4e47b 100644
--- a/tensorflow/core/framework/op.cc
+++ b/tensorflow/core/framework/op.cc
@@ -91,11 +91,15 @@ Status OpRegistry::LookUp(const string& op_type_name,
         }
       }
     }
-    Status status =
-        errors::NotFound("Op type not registered '", op_type_name,
-                         "' in binary running on ", port::Hostname(), ". ",
-                         "Make sure the Op and Kernel are registered in the "
-                         "binary running in this process.");
+    Status status = errors::NotFound(
+        "Op type not registered '", op_type_name, "' in binary running on ",
+        port::Hostname(), ". ",
+        "Make sure the Op and Kernel are registered in the "
+        "binary running in this process. Note that if you "
+        "are loading a saved graph which used ops from "
+        "tf.contrib, accessing (e.g.) `tf.contrib.resampler` should be done"
+        "before importing the graph, as contrib ops are lazily registered "
+        "when the module is first accessed.");
     VLOG(1) << status.ToString();
     return status;
   }
@@ -246,10 +250,15 @@ Status OpListOpRegistry::LookUp(const string& op_type_name,
   auto iter = index_.find(op_type_name);
   if (iter == index_.end()) {
     *op_reg_data = nullptr;
-    return errors::NotFound("Op type not registered '", op_type_name,
-                            "' in binary running on ", port::Hostname(), ". ",
-                            "Make sure the Op and Kernel are registered in the "
-                            "binary running in this process.");
+    return errors::NotFound(
+        "Op type not registered '", op_type_name, "' in binary running on ",
+        port::Hostname(), ". ",
+        "Make sure the Op and Kernel are registered in the "
+        "binary running in this process. Note that if you "
+        "are loading a saved graph which used ops from "
+        "tf.contrib, accessing (e.g.) `tf.contrib.resampler` should be done"
+        "before importing the graph, as contrib ops are lazily registered "
+        "when the module is first accessed.");
   }
   *op_reg_data = iter->second;
   return Status::OK();
diff --git a/tensorflow/core/graph/graph_constructor_test.cc b/tensorflow/core/graph/graph_constructor_test.cc
index c18ccf6ce4..b513778de9 100644
--- a/tensorflow/core/graph/graph_constructor_test.cc
+++ b/tensorflow/core/graph/graph_constructor_test.cc
@@ -3160,5 +3160,20 @@ TEST_F(GraphConstructorTest, ImportGraphDef_ValidateColationConstraints) {
   TF_EXPECT_OK(ImportGraphDef(options, def, &graph_, nullptr));
 }
 
+TEST_F(GraphConstructorTest, ImportGraphDef_UnknownOps) {
+  const string pb_ascii = "node { name: 'op_from_contrib' op: 'OpFromContrib'}";
+  // Try load twice to check for two parts of the error message. We cannot check
+  // for the whole thing in one go because the message includes the hostname.
+  ExpectError(pb_ascii, {"Op type not registered 'OpFromContrib'"});
+  ExpectError(
+      pb_ascii,
+      {"Make sure the Op and Kernel are registered in the "
+       "binary running in this process. Note that if you "
+       "are loading a saved graph which used ops from "
+       "tf.contrib, accessing (e.g.) `tf.contrib.resampler` should be done"
+       "before importing the graph, as contrib ops are lazily registered "
+       "when the module is first accessed."});
+}
+
 }  // namespace
 }  // namespace tensorflow