mjpython bug when installed with uv package manager

[jonzamora]

Hi,

When i try to run a MuJoCo script with mjpython on my Macbook after installing mujoco with the uv package manager, I get an error message. To reproduce the error, I ran the following commands:

# Install `uv` on macOS and Linux.
$ curl -LsSf https://astral.sh/uv/install.sh | sh

# Create project and run mjpython
uv init mujoco-example
cd mujoco-example
uv add mujoco
source .venv/bin/activate
mjpython

The error says the following:

(.venv) jonzamora@mbp mujoco-example % mjpython
failed to dlopen path '/Users/jonzamora/Research/mujoco-example/.venv/bin/python': dlopen(/Users/jonzamora/Research/mujoco-example/.venv/bin/python, 0x000A): Library not loaded: @executable_path/../lib/libpython3.10.dylib
  Referenced from: <4C4C44EE-5555-3144-A1A0-28739E256A39> /Users/jonzamora/.local/share/uv/python/cpython-3.10.14-macos-aarch64-none/bin/python3.10
  Reason: tried: '/Users/jonzamora/Research/mujoco-example/.venv/lib/python3.10/site-packages/mujoco/MuJoCo (mjpython).app/Contents/lib/libpython3.10.dylib' (no such file), '/Users/jonzamora/Research/mujoco-example/.venv/bin/../lib/libpython3.10.dylib' (no such file), '/libpython3.10.dylib' (no such file)

Of course, you could run mjpython main.py, where main.py is a passive viewer rendering script like this:

import time

import mujoco
import mujoco.viewer

m = mujoco.MjModel.from_xml_path('/path/to/mjcf.xml')
d = mujoco.MjData(m)

with mujoco.viewer.launch_passive(m, d) as viewer:
  # Close the viewer automatically after 30 wall-seconds.
  start = time.time()
  while viewer.is_running() and time.time() - start < 30:
    step_start = time.time()

    # mj_step can be replaced with code that also evaluates
    # a policy and applies a control signal before stepping the physics.
    mujoco.mj_step(m, d)

    # Example modification of a viewer option: toggle contact points every two seconds.
    with viewer.lock():
      viewer.opt.flags[mujoco.mjtVisFlag.mjVIS_CONTACTPOINT] = int(d.time % 2)

    # Pick up changes to the physics state, apply perturbations, update options from GUI.
    viewer.sync()

    # Rudimentary time keeping, will drift relative to wall clock.
    time_until_next_step = m.opt.timestep - (time.time() - step_start)
    if time_until_next_step > 0:
      time.sleep(time_until_next_step)

Any help will be greatly appreciated, i'm sure others are also hoping to use a combination of mujoco and uv on their Macbook machines. Thanks!

My Setup

• Operating system + Machine
  • macOS Sonoma, M3 Max Macbook Pro
• MuJoCo version (and if the bug is new, the version where it used to work)
  • MuJoCo 3.2.2
• For Python issues, what bindings are you using (i.e mujoco, dm_control, mujoco-py)?
  • mujoco

[jonzamora]

For comparison, if i create a mamba / conda environment and pip install mujoco, then run mjpython, the expected behavior occurs:

(mujoco) jonzamora@mbp mujoco-example % mjpython
Python 3.10.14 | packaged by conda-forge | (main, Mar 20 2024, 12:51:49) [Clang 16.0.6 ] on darwin
Type "help", "copyright", "credits" or "license" for more information.

[saran-t]

I'm not familiar with uv but it seems that for whatever reason this section of code isn't working properly.

Would you be able to run get_executable_path() from mjpython.py from your non-working venv and tell me what you get?