VectorEnv Initialization Issue.

[Claessens14]

Hello,

I am trying to implement an VectorEnv, where I can run 4 environments together. However I am having an issue.

I am trying to read through the code and was having a hard time understanding everything.
https://aihabitat.org/docs/habitat-lab/habitat.core.vector_env.VectorEnv.html

https://github.com/facebookresearch/habitat-lab/blob/d1df35e675084da53d145b49dce97fe77b314d71/habitat/core/vector_env.py

My habitat version is 0.2.1, and am using an Arm Mac.

    import habitat
    num_envs = 4 
    env_fn_args = [(config,) for _ in range(num_envs)]
    
    def make_env(config):
       return habitat.Env(config=config)

    envs = habitat.core.vector_env.VectorEnv(
        make_env_fn=[make_env for _ in range(num_envs)],
        env_fn_args=env_fn_args
    )

and am getting this error:

objc[5261]: +[NSString initialize] may have been in progress in another thread when fork() was called.
objc[5262]: +[NSString initialize] may have been in progress in another thread when fork() was called.
objc[5261]: +[NSString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[5262]: +[NSString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[5260]: +[NSString initialize] may have been in progress in another thread when fork() was called.
objc[5260]: +[NSString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
objc[5259]: +[NSString initialize] may have been in progress in another thread when fork() was called.
objc[5259]: +[NSString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
Traceback (most recent call last):

  File "/habitat-2022/habitat-lab/dev/run.py", line 125, in <module>
    main()
  File "/habitat-2022/habitat-lab/dev/run.py", line 83, in main
    env = habitat.core.vector_env.VectorEnv(
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 193, in __init__
    self.observation_spaces = [
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 194, in <listcomp>
    read_fn() for read_fn in self._connection_read_fns
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 97, in __call__
    res = self.read_fn()
  File "/habitat-2022/habitat-lab/habitat/utils/pickle5_multiprocessing.py", line 67, in recv
    buf = self.recv_bytes()
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 216, in recv_bytes
    buf = self._recv_bytes(maxlength)
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 414, in _recv_bytes
    buf = self._recv(4)
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 383, in _recv
    raise EOFError
EOFError
Exception ignored in: <function VectorEnv.__del__ at 0x28292aca0>
Traceback (most recent call last):
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 592, in __del__
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 460, in close
  File "/habitat-2022/habitat-lab/habitat/core/vector_env.py", line 97, in __call__
  File "/code/habitat-2022/habitat-lab/habitat/utils/pickle5_multiprocessing.py", line 67, in recv
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 216, in recv_bytes
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 414, in _recv_bytes
  File "/opt/anaconda3/envs/hab_v1/lib/python3.9/multiprocessing/connection.py", line 383, in _recv
EOFError: 
------
Specific function:

/habitat-lab/habitat/utils/pickle5_multiprocessing.py", line 67, in recv
  
   def recv(self):
        self._check_closed()
        self._check_readable()
        buf = self.recv_bytes()

Any help would be greatly appreciated.

Thank you,
Jacob