[Workflow] Default core tasks to RSL-RL (#7067)

Splits the default RL-library change from #6980.\n\n- Resolves
`default_agent` from task registration when `--rl_library` is
omitted.\n- Registers RSL-RL as the default for core tasks, including a
Pendulum RSL-RL config.\n- Adds dispatch coverage and a breaking-change
fragment.\n\nValidation: `uv run python -m pytest
source/isaaclab_rl/test/test_entrypoints.py -q` (11 passed, 2
skipped).\n\nSupersedes the RSL-RL portion of #6980.

Author: StafaH

source/isaaclab_rl/changelog.d/default-rsl-rl.minor.rst

@@ -0,0 +1,6 @@
+Changed
+^^^^^^^
+
+* **Breaking:** Changed the ``train`` and ``play`` CLI commands to use a task's
+  registered default RL library when ``--rl_library`` is omitted. Pass
+  ``--rl_library`` explicitly to select a different library.

source/isaaclab_rl/isaaclab_rl/entrypoints/dispatch.py

@@ -13,6 +13,8 @@
 import sys
 from typing import TYPE_CHECKING
 
+import gymnasium as gym
+
 if TYPE_CHECKING:
     from .simple_agents import PolicyName
 
@@ -106,6 +108,8 @@ def run_cli(action: str, argv: list[str] | None = None) -> int:
     parser = argparse.ArgumentParser(add_help=False)
     parser.add_argument("--rl_library", choices=sorted(backends))
     selected, backend_argv = parser.parse_known_args(argv)
+    if selected.rl_library is None:
+        selected.rl_library = _resolve_default_library(argv, backends)
     if selected.rl_library is None:
         _print_selector_help(action, sorted(backends))
         if "-h" in argv or "--help" in argv:
@@ -116,6 +120,23 @@ def run_cli(action: str, argv: list[str] | None = None) -> int:
     return 0
 
 
+def _resolve_default_library(argv: list[str], backends: dict[str, str]) -> str | None:
+    """Return the task-registered default RL library requested by command-line arguments."""
+    parser = argparse.ArgumentParser(add_help=False)
+    parser.add_argument("--task")
+    args, _ = parser.parse_known_args(argv)
+    if args.task is None:
+        return None
+
+    import isaaclab_tasks  # noqa: F401
+
+    try:
+        default_library = gym.spec(args.task.split(":")[-1]).kwargs.get("default_agent")
+    except gym.error.Error:
+        return None
+    return default_library if default_library in backends else None
+
+
 def _print_selector_help(action: str, backends: list[str]) -> None:
     """Print help for a unified entrypoint before a backend is selected."""
     parser = argparse.ArgumentParser(description=f"{action.capitalize()} an RL agent with a selected backend.")

source/isaaclab_rl/test/test_entrypoints.py

@@ -12,6 +12,7 @@
 import sys
 import types
 
+import gymnasium as gym
 import pytest
 
 from isaaclab_rl.entrypoints import PlaybackRequest, TrainingRequest, api, dispatch
@@ -146,6 +147,32 @@ def _fake_run_backend(module_name: str, argv: list[str], *, run_as_script: bool)
     }
 
 
+def test_dispatch_uses_task_registered_default_backend(monkeypatch) -> None:
+    """A task registry default selects the backend when the CLI omits it."""
+    task_name = "Isaac-DefaultAgentDispatchTest"
+    gym.register(id=task_name, entry_point="dummy:Env", kwargs={"default_agent": "rsl_rl"})
+    monkeypatch.setitem(sys.modules, "isaaclab_tasks", types.ModuleType("isaaclab_tasks"))
+    received: dict[str, object] = {}
+    monkeypatch.setattr(
+        dispatch,
+        "_run_backend",
+        lambda module_name, argv, *, run_as_script: received.update(
+            module_name=module_name, argv=argv, run_as_script=run_as_script
+        ),
+    )
+
+    try:
+        assert dispatch.run_train_cli(["--task", task_name]) == 0
+    finally:
+        gym.registry.pop(task_name, None)
+
+    assert received == {
+        "module_name": "isaaclab_rl.entrypoints.backends.train_rsl_rl",
+        "argv": ["--task", task_name],
+        "run_as_script": False,
+    }
+
+
 def test_dispatch_fuses_option_like_kit_args(monkeypatch) -> None:
     """Space-separated option-like Kit arguments are fused before backend parsing."""
     received: dict[str, object] = {}
@@ -160,7 +187,7 @@ def test_dispatch_fuses_option_like_kit_args(monkeypatch) -> None:
 
 def test_dispatch_requires_a_backend() -> None:
     """Missing backend selection returns the conventional CLI error status."""
-    assert dispatch.run_train_cli(["--task", "Isaac-Cartpole"]) == 2
+    assert dispatch.run_train_cli([]) == 2
 
 
 def _torch_backend_state() -> tuple[bool, bool, bool, bool]:

source/isaaclab_tasks/changelog.d/default-rsl-rl.minor.rst

@@ -0,0 +1,5 @@
+Changed
+^^^^^^^
+
+* **Breaking:** Changed core tasks to use RSL-RL when ``--rl_library`` is omitted, except the multi-agent Pendulum task, which uses SKRL.
+  Pass ``--rl_library`` explicitly to select a different RL library.

source/isaaclab_tasks/isaaclab_tasks/core/cabinet/config/franka/__init__.py

@@ -17,6 +17,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.joint_pos_env_cfg:FrankaCabinetEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:CabinetPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_manager_ppo_cfg.yaml",
         "skrl_cfg_entry_point": f"{agents.__name__}:skrl_manager_ppo_cfg.yaml",
     },
@@ -35,6 +36,7 @@
         "env_cfg_entry_point": f"{__name__}.cabinet_direct_env_cfg:FrankaCabinetDirectEnvCfg",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_direct_ppo_cfg.yaml",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaCabinetPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "skrl_cfg_entry_point": f"{agents.__name__}:skrl_direct_ppo_cfg.yaml",
     },
 )

source/isaaclab_tasks/isaaclab_tasks/core/cartpole/__init__.py

@@ -37,6 +37,7 @@
         "env_cfg_entry_point": f"{__name__}.cartpole_direct_env_cfg:CartpoleEnvCfg",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_direct_ppo_cfg.yaml",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:CartpoleDirectPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "skrl_cfg_entry_point": f"{agents.__name__}:skrl_direct_ppo_cfg.yaml",
         "sb3_cfg_entry_point": f"{agents.__name__}:sb3_ppo_cfg.yaml",
     },
@@ -50,6 +51,7 @@
         "env_cfg_entry_point": f"{__name__}.cartpole_direct_camera_env_cfg:CartpoleCameraEnvCfg",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_camera_ppo_cfg.yaml",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:CartpoleCameraDirectPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "skrl_cfg_entry_point": f"{agents.__name__}:skrl_direct_camera_ppo_cfg.yaml",
     },
 )
@@ -66,6 +68,7 @@
         "env_cfg_entry_point": f"{__name__}.cartpole_manager_env_cfg:CartpoleEnvCfg",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_manager_ppo_cfg.yaml",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:CartpolePPORunnerCfg",
+        "default_agent": "rsl_rl",
         "rsl_rl_with_symmetry_cfg_entry_point": (
             f"{agents.__name__}.rsl_rl_ppo_cfg:CartpolePPORunnerWithSymmetryCfg"
         ),
@@ -83,6 +86,7 @@
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_camera_ppo_cfg.yaml",
         "rl_games_feature_cfg_entry_point": f"{agents.__name__}:rl_games_manager_feature_ppo_cfg.yaml",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:CartpoleCameraPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "rsl_rl_feature_cfg_entry_point": (
             f"{agents.__name__}.rsl_rl_ppo_cfg:CartpoleCameraFeaturePPORunnerCfg"
         ),

source/isaaclab_tasks/isaaclab_tasks/core/fourbar_pole/__init__.py

@@ -20,5 +20,6 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.fourbar_pole_manager_env_cfg:FourbarPoleSwingupEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_manager_ppo_cfg:FourbarPolePPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )

source/isaaclab_tasks/isaaclab_tasks/core/handover/__init__.py

@@ -22,6 +22,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.handover_env_cfg:HandoverEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:HandoverPPORunnerCfg",
+        "default_agent": "rsl_rl",
         "rl_games_cfg_entry_point": f"{agents.__name__}:rl_games_ppo_cfg.yaml",
         "skrl_cfg_entry_point": f"{agents.__name__}:skrl_ppo_cfg.yaml",
         "skrl_ippo_cfg_entry_point": f"{agents.__name__}:skrl_ippo_cfg.yaml",

source/isaaclab_tasks/isaaclab_tasks/core/lift/config/franka/__init__.py

@@ -20,6 +20,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_env_cfg:FrankaReorientEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaPPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )
 
@@ -30,5 +31,6 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_env_cfg:FrankaLiftEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaPPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )

source/isaaclab_tasks/isaaclab_tasks/core/lift/config/franka_soft/__init__.py

@@ -18,6 +18,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_soft_env_cfg:FrankaSoftEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaDeformablePPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )
 
@@ -28,6 +29,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_cloth_env_cfg:FrankaClothEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaClothPPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )
 
@@ -61,6 +63,7 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_soft_env_cfg:FrankaSoftCameraEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaDeformableCameraPPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )
 
@@ -71,5 +74,6 @@
     kwargs={
         "env_cfg_entry_point": f"{__name__}.franka_cloth_env_cfg:FrankaClothCameraEnvCfg",
         "rsl_rl_cfg_entry_point": f"{agents.__name__}.rsl_rl_ppo_cfg:FrankaDeformableCameraPPORunnerCfg",
+        "default_agent": "rsl_rl",
     },
 )