fix None-type not iterable error when deepspeed is left blank w/ use_… (#2087)

* fix None-type not iterable error when deepspeed is left blank w/ use_reentrant: false and qlora

* added unit test[skip e2e]

* corrected test case[skip e2e]

* assert warning message [skip e2e]

* assert warning message [skip e2e]

* corrected test cases [skip e2e]

* lint

src/axolotl/utils/config/models/input/v0_4_1/__init__.py

@@ -1314,6 +1314,7 @@ class AxolotlInputConfig(
             and data.get("gradient_checkpointing_kwargs", {})
             and data.get("gradient_checkpointing_kwargs", {}).get("use_reentrant")
             is False
+            and data.get("deepspeed", "") is not None
             and "zero3" in data.get("deepspeed", "")
         ):
             # may result in:

tests/test_validation.py

@@ -68,6 +68,53 @@ class TestValidation(BaseValidation):
         assert cfg.train_on_inputs is False
         assert cfg.weight_decay is None
 
+    def test_zero3_qlora_use_reentrant_false(self, minimal_cfg):
+        test_cfg = DictDefault(
+            {
+                "deepspeed": "deepspeed_configs/zero3_bf16.json",
+                "gradient_checkpointing": True,
+                "gradient_checkpointing_kwargs": {"use_reentrant": False},
+                "load_in_4bit": True,
+                "adapter": "qlora",
+            }
+            | minimal_cfg
+        )
+
+        with self._caplog.at_level(logging.WARNING):
+            validate_config(test_cfg)
+            assert (
+                "qlora + zero3 with use_reentrant: false may result in a CheckpointError about recomputed values"
+                in self._caplog.records[0].message
+            )
+
+    def test_deepspeed_empty(self, minimal_cfg):
+        test_cfg = DictDefault(
+            {
+                "deepspeed": "",
+                "gradient_checkpointing": True,
+                "gradient_checkpointing_kwargs": {"use_reentrant": False},
+                "load_in_4bit": True,
+                "adapter": "qlora",
+            }
+            | minimal_cfg
+        )
+
+        _ = validate_config(test_cfg)
+
+    def test_deepspeed_not_set(self, minimal_cfg):
+        test_cfg = DictDefault(
+            {
+                "deepspeed": None,
+                "gradient_checkpointing": True,
+                "gradient_checkpointing_kwargs": {"use_reentrant": False},
+                "load_in_4bit": True,
+                "adapter": "qlora",
+            }
+            | minimal_cfg
+        )
+
+        _ = validate_config(test_cfg)
+
     def test_datasets_min_length(self):
         cfg = DictDefault(
             {