Fix for https://github.com/NVIDIA/apex/issues/361

apex/amp/_process_optimizer.py

@@ -284,7 +284,9 @@ def _process_optimizer(optimizer, properties):
             _master_params_to_model_params, optimizer)
 
         old_step = optimizer.step
-        def new_step(self):
+        def new_step(self, closure=None):
+            if closure is not None:
+                raise RuntimeError("Currently, Amp does not support closure use with optimizers.")
             retval = old_step()
             self._master_params_to_model_params()
             # Clear the master grads that wouldn't be zeroed by model.zero_grad()

apex/amp/handle.py

@@ -136,7 +136,9 @@ def scale_loss(loss,
                         # necessary because amp.scale_loss is already creating a temporary scope.
                         def patch_step(opt, loss_scaler, loss_id):
                             opt_step = opt.step
-                            def skip_step():
+                            def skip_step(closure=None):
+                                if closure is not None:
+                                    raise RuntimeError("Currently, Amp does not support closure use with optimizers.")
                                 maybe_print(("Gradient overflow.  Skipping step, loss scaler " +
                                              "{} reducing loss scale to {}").format(loss_id,
                                              loss_scaler.loss_scale()))