[BUG] Using `env.reset()` and `env.async_reset()` results in illegal instructions

[vwxyzjn]

Describe the bug

env.reset() and env.async_reset() results in illegal instructions. This warrants a better error message.

To Reproduce

import envpool
import numpy as np

# make asynchronous
num_envs = 64
batch_size = 16
env = envpool.make("Pong-v5", env_type="gym", num_envs=num_envs, batch_size=batch_size)
action_num = env.action_space.n
env.reset()
env.async_reset()  # send the initial reset signal to all envs
while True:
    obs, rew, done, info = env.recv()
    env_id = info["env_id"]
    action = np.random.randint(action_num, size=batch_size)
    env.send(action, env_id)
    print(action)

[0 4 0 3 1 1 2 1 0 3 0 3 3 4 4 5]
[2 1 0 2 1 2 4 2 5 0 1 0 2 4 2 2]
[1 5 2 0 5 4 1 2 0 1 2 0 0 3 2 0]
[5 5 4 3 5 0 3 5 5 5 2 5 0 2 0 2]
[1 3 5 3 4 2 4 1 1 5 3 5 1 5 5 1]
[5 4 4 1 4 3 2 0 4 1 1 5 2 4 5 5]
[1 0 1 0 1 3 3 3 2 0 0 3 4 5 0 2]
Illegal Instruction! 69
Illegal Instruction! 8a
Illegal Instruction! 2
Illegal Instruction! 2
Illegal Instruction! 2
Illegal Instruction! 2
Illegal Instruction! 2
Illegal Instruction! [4 1 4 1 2 1 2 2 3 2 4 0 5 4 0 2]
2
Illegal Instruction! e8
Illegal Instruction! 30
Illegal Instruction! 2
Illegal Instruction! 38
Illegal Instruction! 84
Illegal Instruction! a
Illegal Instruction! b9
[1 0 1 4 4 5 3 3 2 1 1 4 3 1 0 0]
[2 5 2 1 0 2 5 0 2 3 1 4 4 0 3 3]
[4 0 3 2 5 2 2 4 4 0 2 2 4 4 0 3]
Illegal Instruction! b2
[3 2 3 0 2 1 0 1 4 2 1 0 3 3 2 3]
[4 5 2 3 1 0 2 5 5 2 2 2 5 5 5 4]
[4 1 2 0 5 2 0 2 4 1 4 2 4 0 4 4]
[0 4 2 0 5 4 4 1 2 4 0 0 1 0 4 4]
[2 1 5 4 3 3 2 5 2 2 0 4 5 4 5 0]
[2 0 5 2 3 3 2 4 1 2 4 2 0 0 0 0]
[0 3 1 2 0 5 2 5 1 3 0 3 2 0 4 5]
[1 0 0 3 2 3 2 1 2 4 0 4 4 4 4 2]
[4 2 5 5 4 1 3 2 4 4 4 0 1 3 0 5]
[5 5 0 3 3 4 0 1 3 4 4 3 2 1 5 3]
[2 1 2 2 4 4 2 4 4 3 3 5 2 1 1 3]
Illegal Instruction! 2

Expected behavior

A better error message should be available like saying env.reset() and env.async_reset() cannot be used at the same time.

• [x] I have checked that there is no similar issue in the repo (required)
• [x] I have read the documentation (required)
• [x] I have provided a minimal working example to reproduce the bug (required)

[SobhanMP]

is this safe to ignore?

[Trinkle23897]

No, it is an error you need to care about. By design, envpool never allows users to use multiple reset function calls. You should do either one of the following patterns:

env.async_reset()
env.recv()
env.send(...)
env.recv()
env.send(...)
...

or

env.reset()
env.step(...)
env.step(...)
...

[vwxyzjn]

Makes sense. Closing the issue.