fix(robomimic): unify config loading logic to avoid FileNotFoundError in training

CONTRIBUTORS.md

@@ -89,6 +89,7 @@ Guidelines for modifications:
 * Kourosh Darvish
 * Kousheek Chakraborty
 * Lionel Gulich
+* Litian Gong
 * Lotus Li
 * Louis Le Lay
 * Lorenz Wellhausen

scripts/imitation_learning/robomimic/train.py

@@ -86,6 +86,7 @@
 import isaaclab_tasks  # noqa: F401
 import isaaclab_tasks.manager_based.locomanipulation.pick_place  # noqa: F401
 import isaaclab_tasks.manager_based.manipulation.pick_place  # noqa: F401
+from isaaclab_tasks.utils.parse_cfg import load_cfg_from_registry
 
 
 def normalize_hdf5_actions(config: Config, log_dir: str) -> str:
@@ -361,17 +362,19 @@ def main(args: argparse.Namespace):
         print(f"Loading configuration for task: {task_name}")
         print(gym.envs.registry.keys())
         print(" ")
-        cfg_entry_point_file = gym.spec(task_name).kwargs.pop(cfg_entry_point_key)
-        # check if entry point exists
-        if cfg_entry_point_file is None:
-            raise ValueError(
-                f"Could not find configuration for the environment: '{task_name}'."
-                f" Please check that the gym registry has the entry point: '{cfg_entry_point_key}'."
+
+        # use the unified configuration loading utility (supports YAML, JSON, and Python classes)
+        ext_cfg = load_cfg_from_registry(task_name, cfg_entry_point_key)
+
+        # ensure the configuration is a dictionary (robomimic expects JSON/YAML dict format)
+        if not isinstance(ext_cfg, dict):
+            raise TypeError(
+                f"Expected robomimic configuration to be a dictionary, but got {type(ext_cfg)}."
+                " Please ensure the configuration file is in JSON or YAML format."
             )
 
-        with open(cfg_entry_point_file) as f:
-            ext_cfg = json.load(f)
-            config = config_factory(ext_cfg["algo_name"])
+        # create robomimic config from the loaded dictionary
+        config = config_factory(ext_cfg["algo_name"])
         # update config with external json - this will throw errors if
         # the external config has keys not present in the base algo config
         with config.values_unlocked():

source/isaaclab_tasks/isaaclab_tasks/utils/parse_cfg.py

@@ -80,20 +80,28 @@ def load_cfg_from_registry(task_name: str, entry_point_key: str) -> dict | objec
             f"{msg if agents else ''}"
         )
     # parse the default config file
-    if isinstance(cfg_entry_point, str) and cfg_entry_point.endswith(".yaml"):
+    if isinstance(cfg_entry_point, str) and (cfg_entry_point.endswith(".yaml") or cfg_entry_point.endswith(".json")):
         if os.path.exists(cfg_entry_point):
             # absolute path for the config file
             config_file = cfg_entry_point
         else:
             # resolve path to the module location
             mod_name, file_name = cfg_entry_point.split(":")
-            mod_path = os.path.dirname(importlib.import_module(mod_name).__file__)
+            mod = importlib.import_module(mod_name)
+            if mod.__file__ is None:
+                raise ValueError(f"Could not determine file path for module: {mod_name}")
+            mod_path = os.path.dirname(mod.__file__)
             # obtain the configuration file path
             config_file = os.path.join(mod_path, file_name)
         # load the configuration
         print(f"[INFO]: Parsing configuration from: {config_file}")
         with open(config_file, encoding="utf-8") as f:
-            cfg = yaml.full_load(f)
+            if cfg_entry_point.endswith(".yaml"):
+                cfg = yaml.full_load(f)
+            else:  # .json
+                import json
+
+                cfg = json.load(f)
     else:
         if callable(cfg_entry_point):
             # resolve path to the module location