MoJoCo with miniconda3 environment

[aleada23]

Intro

Hi!

I am a PhD student, and I would like to use MuJoCo for my research in RL.

My setup

I'm using MuJoCo 3.3.5 with Ubuntu 22.04.

My question

I'm forced to use miniconda3 virtual environment to run simulations, but I am unable to render them. The code works if I deactivate the environment. I tried to fix it by looking online (it should be a known problem) for a solution, and tried to follow the guidelines but the problem remains. The output error is: libEGL warning: MESA-LOADER: failed to open iris: /usr/lib/dri/iris_dri.so: cannot open shared object file: No such file or directory (search paths /usr/lib/x86_64-linux-gnu/dri:$${ORIGIN}/dri:/usr/lib/dri, suffix _dri)

libEGL warning: MESA-LOADER: failed to open swrast: /usr/lib/dri/swrast_dri.so: cannot open shared object file: No such file or directory (search paths /usr/lib/x86_64-linux-gnu/dri:$${ORIGIN}/dri:/usr/lib/dri, suffix _dri)

/home/alead/miniconda3/envs/mujoco_env/lib/python3.12/site-packages/glfw/init.py:917: GLFWError: (65542) b'EGL: Failed to initialize EGL: EGL is not or could not be initialized'
warnings.warn(message, GLFWError)
ERROR: could not create window

Thank you in advance for your help

Minimal model and/or code that explain my question

No response

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[driesmarzougui]

The dm_control package's README contains some helpful instructions with respect to rendering: https://github.com/google-deepmind/dm_control?tab=readme-ov-file#rendering

[traversaro]

What you mean with "the code works" if you deactivated the environment? Can you report your conda list?

[aleada23]

I installed it outside the environment on my laptop to test it.
I created a new environment and installed mujoco:
conda create -n myenv python=3.12
conda activate new_env
pip install mujoco

Without installing OpenGL libraries, the outcome is AttributeError: 'NoneType' object has no attribute 'glGetError'.
This is the conda list for the new environment:
Name Version Build Channel
_libgcc_mutex 0.1 main
_openmp_mutex 5.1 1_gnu
absl-py 2.3.1 pypi_0 pypi
bzip2 1.0.8 h5eee18b_6
ca-certificates 2025.7.15 h06a4308_0
etils 1.13.0 pypi_0 pypi
expat 2.7.1 h6a678d5_0
fsspec 2025.7.0 pypi_0 pypi
glfw 2.9.0 pypi_0 pypi
importlib-resources 6.5.2 pypi_0 pypi
ld_impl_linux-64 2.40 h12ee557_0
libffi 3.4.4 h6a678d5_1
libgcc-ng 11.2.0 h1234567_1
libgomp 11.2.0 h1234567_1
libstdcxx-ng 11.2.0 h1234567_1
libuuid 1.41.5 h5eee18b_0
libxcb 1.17.0 h9b100fa_0
mujoco 3.3.5 pypi_0 pypi
ncurses 6.5 h7934f7d_0
numpy 2.3.2 pypi_0 pypi
openssl 3.0.17 h5eee18b_0
pip 25.2 pyhc872135_0
pthread-stubs 0.3 h0ce48e5_1
pyopengl 3.1.10 pypi_0 pypi
python 3.12.11 h22baa00_0
readline 8.3 hc2a1206_0
setuptools 78.1.1 py312h06a4308_0
sqlite 3.50.2 hb25bd0a_1
tk 8.6.15 h54e0aa7_0
typing-extensions 4.15.0 pypi_0 pypi
tzdata 2025b h04d1e81_0
wheel 0.45.1 py312h06a4308_0
xorg-libx11 1.8.12 h9b100fa_1
xorg-libxau 1.0.12 h9b100fa_0
xorg-libxdmcp 1.1.5 h9b100fa_0
xorg-xorgproto 2024.1 h5eee18b_1
xz 5.6.4 h5eee18b_1
zipp 3.23.0 pypi_0 pypi
zlib 1.2.13 h5eee18b_1

[traversaro]

Ok, the situation now is much more clear. Can you install with conda libegl-devel and try again? I assume you are trying to load by setting MUJOCO_GL=egl ? Is this an headless system?

[aleada23]

Yes, I'm trying with MUJOCO_GL=egl. I also tried to lunch some robosuite demos in the first environment and the result was the same.

I installed libegl-devel with conda install conda-forge::libegl-devel, and the outcome is the same. I tried creating a new environment and installing mujoco with conda install conda-forge::mujoco-python in place of using pip. In this case, the outcome is: You are using a GLFW raw input patch. This is not the official GLFW library.
Segmentation fault (core dumped).

[traversaro]

That is strange. Are you sure that you do not have any strange library installed in your system? You can look at the library loaded by setting LD_DEBUG=libs env variable. What is the snippet of code you are trying to run? Is the system headless or not? Can you reproduce the issue in a docker container?

[aleada23]

In the docker the code runs properly. I tried to download the MuJoCo .zip and launch after conda activation with the call ./simulate ../test_empty_world.xml (my test .xml), and it works too.
The snippet of code that I'm trying to launch is:
`import mujoco
import mujoco.viewer
import os
os.environ["MUJOCO_GL"] = "egl"

MODEL_PATH = "../environments/assets/test_empty_world.xml"

model = mujoco.MjModel.from_xml_path(MODEL_PATH)
data = mujoco.MjData(model)

with mujoco.viewer.launch_passive(model, data) as viewer:
while viewer.is_running():
mujoco.mj_step(model, data)
viewer.sync()`