Update env.py

env.py

@@ -1,3 +1,4 @@
+# env.py
 
 from pathlib import Path
 import subprocess
@@ -6,7 +7,10 @@ import gymnasium as gym
 from gymnasium import spaces
 import numpy as np
 from huggingface_hub import snapshot_download
-snapshot_download(repo_id='lerobot/unitree-g1-mujoco', revision=None, cache_dir=None)
+
+# ensure the repo snapshot exists (no-op if already cached)
+snapshot_download(repo_id="lerobot/unitree-g1-mujoco", revision=None, cache_dir=None)
+
 
 def make_env(
     n_envs=1,
@@ -17,11 +21,10 @@ def make_env(
     **kwargs,
 ):
     """
-    just launch run_sim.py as a subprocess (non-blocking)
+    launch run_sim.py as a subprocess (non-blocking),
     then return a dummy gym env.
     """
 
-    # path to this repo's run_sim.py
     repo_dir = Path(__file__).parent
     run_sim = repo_dir / "run_sim.py"
 
@@ -30,16 +33,11 @@ def make_env(
     print("path:", run_sim)
     print("=" * 60)
 
-    # subprocess: completely independent simulator
-    proc = subprocess.Popen(
-        [sys.executable, str(run_sim)],
-        stdout=subprocess.PIPE,
-        stderr=subprocess.STDOUT,
-    )
+    # start simulator as independent process, inherit stdout/stderr
+    proc = subprocess.Popen([sys.executable, str(run_sim)])
 
     print(f"simulator started as pid={proc.pid}")
 
-    # minimal env for envhub
     class DummyEnv(gym.Env):
         metadata = {"render_modes": []}
 
@@ -56,11 +54,13 @@ def make_env(
             return np.zeros(1, dtype=np.float32), 0.0, False, False, {}
 
         def close(self):
-            if self.process.poll() is None:
-                print("terminating simulator subprocess...")
-                self.process.terminate()
+            # important: do NOT kill the simulator here
+            # envhub / launch_env will call close() immediately;
+            # we want run_sim.py to keep running.
+            pass
 
         def run(self):
+            # kept for api symmetry, but unused when wrapped in SyncVectorEnv
             pass
 
     return DummyEnv(proc)