no backend in latest colab

[aduchon]

Opening a brand new google colab (GPU or TPU) with simply:

!pip install vispy
import vispy
vispy.test()

It errors on every backend, ending with

Testing failed (['nobackend'] failed, ['pyqt4', 'pyqt5', 'pyqt6', 'pyside', 'pyside2', 'pyside6', 'pyglet', 'glfw', 'sdl2', 'wx', 'egl', 'osmesa', 'jupyter_rfb', '_test', 'examples'] skipped) in 4.874 seconds
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
[<ipython-input-1-2164daa7587a>](https://localhost:8080/#) in <cell line: 4>()
      2 
      3 import vispy
----> 4 vispy.test()

1 frames
[/usr/local/lib/python3.9/dist-packages/vispy/testing/_runners.py](https://localhost:8080/#) in test(label, extra_arg_string, coverage)
    444     sys.stdout.flush()
    445     if len(fail) > 0:
--> 446         raise RuntimeError('FAILURE')

RuntimeError: FAILURE

I hadn't tried using vispy before this week, so I don't know if this ever worked in a colab. I know other AI-related colabs have recently broken though. Is there a way to ensure a backend in a colab?

[djhoese]

As stated in the install instructions, vispy does not install any backend by default. It is up to the user to install tye necessary dependencies. I don't know what platform colab runs on but you could try installing pyqt and see how that goes. Let us know how it goes.

[djhoese]

Feel free to continue to comment here, but I'm not sure this is anything wrong or changed in vispy. Closing now. We can reopen if it turns out to be something needing fixing in vispy.

[danilw]

Well this is problem of Vispy it seems, or Google banned single Vispy package from accessing EGL.
I mean Vispy was working before with EGL on Colab, I have scripts I used so I know, and does not work anymore.
Only what changed on Colab as I know - they updated Nvidia driver to 525.85.12 version.
Nvidia driver update or Google block Vispy somehow, this is two cases I can see.

!pip install vispy

import vispy
vispy.use('EGL')
print(vispy.sys_info())

When on same Colab running moderngl EGL backend - works.

!pip install moderngl
and copy example from Wrong link look below for correct link

I tried few old versions of Vispy - same result.
Also tried other backends on Vispy - I have not found any working with OpenGL acceleration working.

[djhoese]

Looks like EGL is available but can't be initialized:

This says to me that something has changed about the EGL installation or that colab used to create a virtual display but doesn't anymore:

https://stackoverflow.com/a/66952101/433202

I'll see if I can learn anything else. I know very little about EGL and no absolutely nothing about moderngl.

[djhoese]

How exactly are you running moderngl examples? Did you download moderngl source? The example you linked to imports the relatively available ported package in the same directory which accesses a data directory in the examples folder.

[djhoese]

Looking through moderngl source and its glcontext library I see custom EGL and X11 backends. The X11 default backend doesn't seem to initialize on colab, but EGL does. I'd have to compare their EGL C++ backend to our ctypes EGL backend.

[djhoese]

As best I can tell the EGL functions called by glcontext are available from a "newer" extension to EGL: https://registry.khronos.org/EGL/extensions/EXT/EGL_EXT_platform_base.txt

And are used here: https://github.com/moderngl/glcontext/blob/8a6918336869296565a0cb4a6c7c510f26443762/glcontext/egl.cpp#L208-L237

Vispy's EGL usage does not use (or assume) that this extension is available, but apparently it should as it would make it work in more instances. Here's where Vispy uses these EGL functions:

vispy/vispy/ext/egl.py

Lines 235 to 250 in d776344

	def eglGetDisplay(display=EGL_DEFAULT_DISPLAY):
	"""Connect to the EGL display server."""
	res = _lib.eglGetDisplay(display)
	if not res or res == EGL_NO_DISPLAY:
	raise RuntimeError('Could not create display')
	return c_void_p(res)
	def eglInitialize(display):
	"""Initialize EGL and return EGL version tuple."""
	majorVersion = (_c_int*1)()
	minorVersion = (_c_int*1)()
	res = _lib.eglInitialize(display, majorVersion, minorVersion)
	if res == EGL_FALSE:
	raise RuntimeError('Could not initialize')
	return majorVersion[0], minorVersion[0]

CC @almarklein @rougier who I think have more experience with this type of stuff.

[danilw]

How exactly are you running moderngl examples?

1. !pip install moderngl
2. I linked wrong example before, correct is https://github.com/moderngl/moderngl/blob/master/examples/headless_egl.py
3. press Runtime-Run all

to display rendered image on Colab

from IPython.display import Image
Image('triangle.png')

---

[danilw]

The example you linked to imports the relatively available ported package in the same directory which accesses a data directory in the examples folder.

I linked wrong example. sorry.

Correct example is https://github.com/moderngl/moderngl/blob/master/examples/headless_egl.py