add backbone override to hydra

src/fairchem/core/models/base.py

@@ -251,6 +251,11 @@ def __init__(
         # if finetune_config is provided, then attempt to load the model from the given finetune checkpoint
         starting_model = None
         if finetune_config is not None:
+            # Make it hard to sneak more fields into finetuneconfig
+            assert (
+                len(set(finetune_config.keys()) - {"starting_checkpoint", "override"})
+                == 0
+            )
             starting_model: HydraModel = load_model_and_weights_from_checkpoint(
                 finetune_config["starting_checkpoint"]
             )
@@ -260,6 +265,10 @@ def __init__(
             assert isinstance(
                 starting_model, HydraModel
             ), "Can only finetune starting from other hydra models!"
+            # TODO this is a bit hacky to overrride attrs in the backbone
+            if "override" in finetune_config:
+                for key, value in finetune_config["override"].items():
+                    setattr(starting_model.backbone, key, value)
 
         if backbone is not None:
             backbone = copy.deepcopy(backbone)

tests/core/e2e/test_e2e_finetune_hydra.py

@@ -283,6 +283,38 @@ def test_finetune_hydra_retain_backbone(tutorial_val_src):
             )
 
 
+def test_finetune_hydra_override(tutorial_val_src):
+    with tempfile.TemporaryDirectory() as orig_ckpt_dir:
+        starting_ckpt = make_checkpoint(orig_ckpt_dir, tutorial_val_src, 0)
+        # now finetune a the model with the checkpoint from the first job
+        with tempfile.TemporaryDirectory() as ft_temp_dir:
+            ft_yml = Path("tests/core/models/test_configs/test_finetune_hydra.yml")
+            ck_ft_path = os.path.join(ft_temp_dir, "checkpoint_ft.pt")
+            model_config = {
+                "name": "hydra",
+                "finetune_config": {
+                    "starting_checkpoint": starting_ckpt,
+                    "override": {"forward": None},
+                },
+                "heads": {
+                    "energy": {"module": "equiformer_v2_energy_head"},
+                    "forces": {"module": "equiformer_v2_force_head"},
+                },
+            }
+
+            # TODO add a better test for override when we get there
+            # for now just override .forward() with None
+            with pytest.raises(TypeError):
+                run_main_with_ft_hydra(
+                    tempdir=ft_temp_dir,
+                    yaml=ft_yml,
+                    data_src=tutorial_val_src,
+                    run_args={"seed": 1000},
+                    model_config=model_config,
+                    output_checkpoint=ck_ft_path,
+                )
+
+
 def test_finetune_hydra_data_only(tutorial_val_src):
     with tempfile.TemporaryDirectory() as orig_ckpt_dir:
         starting_ckpt = make_checkpoint(orig_ckpt_dir, tutorial_val_src, 0)