Error to load the Qt platform plugin "xcb"

[hellkonig]

To whom it may concern,

I have encountered some issues while trying to run the demo test for iGibson. I was able to successfully install iGibson and load it in ipython without any problems. However, when I tried to run the demo test using the command python -m igibson.examples.environments.env_nonint_example, I received the following error message:

torch is not available, falling back to rendering to memory (instead of tensor)
********************************************************************************
Description:
    Creates an iGibson environment from a config file with a turtlebot in Rs (not interactive).
    It steps the environment 100 times with random actions sampled from the action space,
    using the Gym interface, resetting it 10 times.
    ********************************************************************************
INFO:igibson.render.mesh_renderer.get_available_devices:Device 0 is available for rendering
INFO:igibson.render.mesh_renderer.get_available_devices:Command '['/home/wan325/miniconda3/envs/igibson/lib/python3.8/site-packages/igibson/render/mesh_renderer/build/test_device', '1']' returned non-zero exit status 1.
INFO:igibson.render.mesh_renderer.get_available_devices:Device 1 is not available for rendering
INFO:igibson.render.mesh_renderer.get_available_devices:Device 2 is available for rendering
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/wan325/miniconda3/envs/igibson/lib/python3.8/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb.

Aborted (core dumped)

I have also installed the latest version of Qt (QMake version 3.1 and Qt version 5.12.8 in /usr/lib/x86_64-linux-gnu), so I don't think the issue is related to the Qt installation.

Additionally, I tried to test the iGibson installation by following the instructions to run pytest --ignore disabled --ignore benchmark, but I received the following error message:

ERROR: usage: pytest [options] [file_or_dir] [file_or_dir] [...]
pytest: error: unrecognized arguments: --cov=igibson --cov-report=xml
  inifile: /home/wan325/Documents/projects/active_object_detection/iGibson/pyproject.toml
  rootdir: /home/wan325/Documents/projects/active_object_detection/iGibson

I would appreciate any assistance in resolving these issues so that I can continue working with iGibson. Thank you for your time and attention.

[ChengshuLi]

This might be because you are running on a cluster machine without a display (monitor) connected to it.

You can either set headless=True in the line below or run the code on a machine that has a display.

https://github.com/StanfordVL/iGibson/blob/7d9598278b95ec1039e1f4366c66b45346521e44/igibson/examples/environments/env_nonint_example.py#L13

[hellkonig]

Hi Chengshu, thank you very much for your suggestion. I tried setting headless=True in the line as you suggested, and it worked perfectly fine when running the code in headless mode.

However, I also tried to run the code on my laptop without headless mode and faced another error in the following:

INFO:igibson.render.mesh_renderer.get_available_devices:Device 0 is available for rendering
INFO:igibson.render.mesh_renderer.get_available_devices:Command '['/home/wan325/miniconda3/envs/igibson/lib/python3.8/site-packages/igibson/render/mesh_renderer/build/test_device', '1']' returned non-zero exit status 1.
INFO:igibson.render.mesh_renderer.get_available_devices:Device 1 is not available for rendering
INFO:igibson.render.mesh_renderer.get_available_devices:Device 2 is available for rendering
ERROR: Failed to EGL with glad.

That is why I unset the $DISPLAY variable. Could you please advise me on how to solve this issue if I want to run the code not in headless mode?

Thank you for your time and support.

[linkct]

Same here. I ran the docker command docker run --env="DISPLAY" --volume="/tmp/.X11-unix:/tmp/.X11-unix:rw" --env="QT_X11_NO_MITSHM=1" --gpus all -ti --rm igibson/igibson on a local Ubuntu 20.04 workstation, but running python -m igibson.examples.environments.env_nonint_example inside the container gave me the following error:

qt.qpa.xcb: could not connect to display :0
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/miniconda/envs/igibson/lib/python3.8/site-packages/cv2/qt/plugins" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb.

Aborted (core dumped)

I can confirm that the DISPLAY environment variable is indeed set to :0, which seems to be the source of the problem, but running GUI applications outside the container is completely normal (e.g. glxgears), so I'm not sure how to fix this. Thanks for any help!

[unnikrishnanrnair]

(for running on a local machine with a monitor attached) running this on the host machine xhost +local:docker before starting the docker container and running the example script worked for me. @linkct