    def test_activation_checkpointing_does_not_change_metrics(self):
        """--checkpoint-activations should not change loss"""

        with tempfile.TemporaryDirectory("test_transformer_with_act_cpt") as data_dir:
            with self.assertLogs():
                create_dummy_data(data_dir, num_examples=20)
                preprocess_translation_data(data_dir)
            ckpt_logs = self._train(data_dir, ["--checkpoint-activations"])
            baseline_logs = self._train(data_dir, [])
            assert len(baseline_logs) == len(ckpt_logs)

            baseline_train_stats = read_last_log_entry(baseline_logs, "train")
            ckpt_train_stats = read_last_log_entry(ckpt_logs, "train")
            assert baseline_train_stats["train_loss"] == ckpt_train_stats["train_loss"]

            baseline_valid_stats = read_last_log_entry(baseline_logs, "valid")
            ckpt_valid_stats = read_last_log_entry(ckpt_logs, "valid")
            assert baseline_valid_stats["valid_loss"] == ckpt_valid_stats["valid_loss"]
--checkpoint-activations should not change loss
tests/test_binaries.py