Segmentation fault when imported with other mujoco dependent packages

Describe the bug I have an OpenAI Gym library (https://github.com/p-morais/gym-cassie) that uses a custom ctypes wrapper for a C library that uses MuJoCo 1.5. The problem is when I import my library AND the gym mujoco envs, gym.make("Walker2d-v2") etc triggers a segfault. They are using separate versions of Mujoco (1.5 vs 2.0) so that may have something to do with it. I posted the gdb trace below.

To Reproduce I'm not sure what the minimal reproducible code is, but provided you have gym_cassie installed (which is easy with pip install provided you have mjpro150 and mjkey.txt in ~/.mujoco) then the following triggers it:

import gym
import gym_cassie
gym.make("Walker2d-v2")

Expected behavior Should either support both environments being imported, or should fail gracefully without segfaulting.

Error Messages Running in gdb produces:

Program received signal SIGSEGV, Segmentation fault.
0x00007fffd3ce8192 in __pyx_f_9mujoco_py_4cymj_9PyMjModel__extract_mj_names (
    __pyx_v_self=__pyx_v_self@entry=0x555556af0308, 
    __pyx_v_p=__pyx_v_p@entry=0x5555572c3c10, 
    __pyx_v_name_adr=<optimized out>, __pyx_v_n=8, 
    __pyx_v_obj_type=__pyx_v_obj_type@entry=mjOBJ_BODY)
    at /home/beast/p-morais/mjp/mujoco-py/mujoco_py/cymj.c:24106
24106       __pyx_v_name = (__pyx_v_p->names + (__pyx_v_name_adr[__pyx_v_i]));

Desktop (please complete the following information):

OS: Ubuntu 18.04
Python Version: 3.6.8
Mujoco Version: 2.0
mujoco-py version: 2.0.20

Environment

output of: echo $LD_LIBRARY_PATH :/home/beast/.mujoco/mujoco200/bin
output of: echo $HOME /home/beast
output of: echo $USER beast

openai / mujoco-py

Segmentation fault when imported with other mujoco dependent packages #392