Error in gym-super-mario-bros package

[dileepmatha]

When running the program
`from nes_py.wrappers import BinarySpaceToDiscreteSpaceEnv
import gym_super_mario_bros
from gym_super_mario_bros.actions import SIMPLE_MOVEMENT
env = gym_super_mario_bros.make('SuperMarioBros-v0')
env = BinarySpaceToDiscreteSpaceEnv(env, SIMPLE_MOVEMENT)

done = True
for step in range(5000):
if done:
state = env.reset()
state, reward, done, info = env.step(env.action_space.sample())
env.render()

env.close()`
I am getting the error

Traceback (most recent call last): File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/init.py", line 378, in getattr return getattr(self._module, name) AttributeError: 'NoneType' object has no attribute '_create_shadow_window' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "", line 5, in File "/home/dileep/.local/lib/python3.6/site-packages/gym/core.py", line 237, in render return self.env.render(mode, **kwargs) File "/home/dileep/.local/lib/python3.6/site-packages/gym/core.py", line 237, in render return self.env.render(mode, **kwargs) File "/home/dileep/.local/lib/python3.6/site-packages/nes_py/nes_env.py", line 364, in render from ._image_viewer import ImageViewer File "/home/dileep/.local/lib/python3.6/site-packages/nes_py/_image_viewer.py", line 2, in from pyglet.window import Window File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/window/init.py", line 1896, in gl._create_shadow_window() File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/init.py", line 384, in getattr import(import_name) File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/gl/init.py", line 100, in from pyglet.gl.lib import GLException File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/gl/lib.py", line 143, in from pyglet.gl.lib_glx import link_GL, link_GLU, link_GLX File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/gl/lib_glx.py", line 50, in gl_lib = pyglet.lib.load_library('GL') File "/home/dileep/.local/lib/python3.6/site-packages/pyglet/lib.py", line 158, in load_library raise ImportError('Library "%s" not found.' % names[0]) ImportError: Library "GL" not found.