pyvirtualdisplay not visible [HANDS-ON BUG]

[blexo]

Describe the bug

I may be misunderstanding - the class text is not clear on this point, but when I run:

from pyvirtualdisplay import Display
virtual_display = Display(visible=0, size=(1400, 900))
virtual_display.start()

I do not see a display screen... I notice that visible=0 in the code - but if I try to set it to one, it crashes with:
No such file or directory: 'Xephyr'

Is this lesson supposed to display a screen - or is this just a context for the gymnasium library to operate in?

Also - just an aside, the class content on the HuggingFace site is not in sync with the code in this github repo... the code on the site still uses old code that fails to install libraries for example:

apt install python-opengl

Material

• Did you use Google Colab?
  Yes

[simoninithomas]

Hey there 👋 it's just a context for the gymnasium library to operate in. There's no screen which will be displayed in your browser. It's just a virtual screen system that allows us to record frames to generate a video when you push your model on the Hub.

You mean the course section is not updated like the Google colab?

[blexo]

Hi @simoninithomas, sorry for the delay... I got busy. Here is what I mean by course mismatch... on this "hands on" page on the hugging face site: https://huggingface.co/learn/deep-rl-course/unit1/hands-on

you say to set up using this code:

sudo apt-get update
apt install python-opengl
apt install ffmpeg
apt install xvfb
pip3 install pyvirtualdisplay

This method fails

Here on github you have the same notebook here:
https://github.com/huggingface/deep-rl-class/blob/main/notebooks/unit1/unit1.ipynb

and you say to set up using this code:

!sudo apt-get update
!sudo apt-get install -y python3-opengl
!apt install ffmpeg
!apt install xvfb
!pip3 install pyvirtualdisplay

This method works

I will proceed by using the github notebooks... but I'm guessing people that are following the course directly on huggingface are having problems and giving up

[blexo]

And also - thank you making this course... I have been reading the sutton book and working through the exercises... but this presentation is much more congenial and has modern hands on examples. Very great!