Vispy example throws "RuntimeError: Cannot FRAMEBUFFER object X because it does not exist"

[gselzer]

Here's a MCVE reproducing the error, running within a local copy of jupyter_rfb:

uv venv
uv pip install -e "."
uv pip install "vispy @ git+https://github.com/vispy/vispy" glfw jupyter
uv run --no-sync jupyter notebook examples/vispy1.ipynb

Running the single cell yields

Traceback (most recent call last):
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\jupyter_rfb\widget.py", line 288, in _rfb_maybe_draw
    array = self.get_frame()
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\app\backends\_jupyter_rfb.py", line 205, in get_frame
    self._vispy_canvas.context.flush_commands()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\gloo\context.py", line 172, in flush_commands
    self.glir.flush(self.shared.parser)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\gloo\glir.py", line 584, in flush
    self._shared.flush(parser)
    ~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\gloo\glir.py", line 506, in flush
    parser.parse(self._filter(self.clear(), parser))
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\gloo\glir.py", line 824, in parse
    self._parse(command)
    ~~~~~~~~~~~^^^^^^^^^
  File "C:\Users\gjselzer\code\vispy\jupyter_rfb\.venv\Lib\site-packages\vispy\gloo\glir.py", line 780, in _parse
    raise RuntimeError('Cannot %s object %i because it '
                       'does not exist' % (cmd, id_))
RuntimeError: Cannot FRAMEBUFFER object 23 because it does not exist

I'm not a GL expert, so I don't really know where to start debugging this, however the issue maybe should be transferred to the vispy repo?

[almarklein]

I can reproduce this on Windows (but not on osx). Do you know whether this is a new issue (since 1.0)?

edit: it looks like with jupyter_rfb 0.5.4 it gives a different error 🤔: OSError: exception: access violation reading 0x0000000000000B98

[almarklein]

Debugging this is a nightmare. Jupyter swallows errors, print(), and even writing to sys.stdout. On windows, a callback passed to loop.call_soon(..) is not evaluated until another cell is run, but on MacOS this works fine? Fuckin' hell.

[gselzer]

Do you know whether this is a new issue (since 1.0)?

As you've noticed, this particular message is recent, but I think the problem has existed since before 1.0. I do remember these examples working on Windows in 2025, but couldn't tell you more, sorry!

edit: it looks like with jupyter_rfb 0.5.4 it gives a different error 🤔: OSError: exception: access violation reading 0x0000000000000B98

Yeah, I saw that too - I didn't explicitly mention it as to my untrained eye it might have a similar cause as the one we see on 1.0.2?

Debugging this is a nightmare.

It really is, I tried for an hour or two but didn't have anything to report 🙃 . I did have better luck with debug running the example within VSCode, which should be better thanks to anywidget!

[almarklein]

This also looks similar to #121; the error is in the same code-path (glir code related to frame buffers). It looks a lot like commands are send in the wrong order (i.e. framebuffer being used before it's created or something).

I'll have another try tomorrow, when I have access to the Windows machine in my office.

[almarklein]

Hehe, that's interesting:

https://github.com/vispy/vispy/blob/c1391870f320a47f45f3c18c4038db02273973dd/vispy/app/backends/_jupyter_rfb.py#L213-L215

[gselzer]

Hehe, that's interesting:

https://github.com/vispy/vispy/blob/c1391870f320a47f45f3c18c4038db02273973dd/vispy/app/backends/_jupyter_rfb.py#L213-L215

Yeah, I noticed that. Part of my debugging was flushing in various places in addition to that spot, but no additional flushes seemed to help 😅

Again, I didn't try too hard, been busy with other priorities at the moment

[almarklein]

Debug trick, add this to the notebook cell:

import sys, logging
sys.print = canvas._backend.print
logger = logging.getLogger('vispy')
class Handler(logging.Handler):
    def emit(self, record):
        sys.print(record.name, record.levelname, record.getMessage())
logger.addHandler(Handler())

That way vispy's loged warnings and errors are actually visible. And you can add sys.print() where needed to get some more feedback. I find it super-weird that this is needed; who thought that hiding stdout/stderr was a good idea?

Anyway, the cause seems to be that the OpenGL context could not be created correctly. Eventually this causes the creation of the framebuffer to fail, which explains the error when the framebuffer is deactivated that was actually shown. The offscreen context uses glfw by default to create a hidden window to provide a context. It falls back to using other GUI backends, the same error happens when I use Qt. And both glfw and Qt with normal examples on my system.

My time (and ability to deal with frustration) is up for the moment. I may look at this again another day. But the above may help someone else to dive further.

[almarklein]

Here's the logged warnings and tracebacks:

Details

vispy WARNING OpenGL version could not be determined, which might be a sign that OpenGL is not loaded correctly.
vispy WARNING Error drawing visual 
vispy WARNING Traceback (most recent call last):
  File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\threading.py", line 1014, in _bootstrap
    self._bootstrap_inner()
  File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\threading.py", line 1043, in _bootstrap_inner
    self.run()
  File "C:\Users\almar\dev\.venv\Lib\site-packages\ipykernel\subshell.py", line 38, in run
    super().run()
  File "C:\Users\almar\dev\.venv\Lib\site-packages\ipykernel\thread.py", line 24, in run
    self.io_loop.start()
  File "C:\Users\almar\dev\.venv\Lib\site-packages\tornado\platform\asyncio.py", line 211, in start
    self.asyncio_loop.run_forever()
  File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\base_events.py", line 683, in run_forever
    self._run_once()
  File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\base_events.py", line 2050, in _run_once
    handle._run()
  File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\events.py", line 89, in _run
    self._context.run(self._callback, *self._args)
  File "C:\Users\almar\dev\py\jupyter_rfb\jupyter_rfb\widget.py", line 289, in _rfb_maybe_draw
    array = self.get_frame()
  File "C:\Users\almar\dev\py\vispy\vispy\app\backends\_jupyter_rfb.py", line 210, in get_frame
    self._vispy_canvas.events.draw(region=None)
  File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 453, in __call__
    self._invoke_callback(cb, event)
  File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 471, in _invoke_callback
    _handle_exception(self.ignore_callback_errors,
  << caught exception here: >>
  File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl\_gl2.py", line 53, in glBindFramebuffer
    nativefunc = glBindFramebuffer._native
                 ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'function' object has no attribute '_native'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl\gl2.py", line 70, in get_gl_func

func = getattr(lib, name)

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\ctypes_init.py", line 403, in getattr

func = self.getitem(name)

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\ctypes_init.py", line 408, in getitem

func = self._FuncPtr((name_or_ordinal, self))

AttributeError: function 'glBindFramebuffer' not found
During handling of the above exception, another exception occurred:
Traceback (most recent call last):

File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 469, in _invoke_callback

cb(event)

~~^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\scene\canvas.py", line 226, in on_draw

self._draw_scene()

~~~~~~~~~~~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\scene\canvas.py", line 285, in _draw_scene

self.draw_visual(self.scene)

~~~~~~~~~~~~~~~~^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\scene\canvas.py", line 323, in draw_visual

node.draw()

~~~~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\scene\visuals.py", line 106, in draw

self._visual_superclass.draw(self)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\visuals\visual.py", line 668, in draw

v.draw()

~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\visuals\visual.py", line 514, in draw

self._program.draw(self._vshare.draw_mode,

~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^

self._vshare.index_buffer)

^^^^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\visuals\shaders\program.py", line 102, in draw

Program.draw(self, *args, **kwargs)

~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\program.py", line 544, in draw

canvas.context.flush_commands()

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\context.py", line 171, in flush_commands

self.shared.parser.parse([('CURRENT', 0, fbo)])

~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 824, in parse

self._parse(command)

~~~~~~~~~~~^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 752, in _parse

gl.glBindFramebuffer(gl.GL_FRAMEBUFFER, args[0])

~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl_gl2.py", line 55, in glBindFramebuffer

nativefunc = glBindFramebuffer._native = _get_gl_func("glBindFramebuffer", None, (ctypes.c_uint, ctypes.c_uint,))

~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl\gl2.py", line 85, in _get_gl_func

raise RuntimeError('Using %s with no OpenGL context.' % name)

RuntimeError: Using glBindFramebuffer with no OpenGL context.

vispy ERROR Invoking <bound method SceneCanvas.on_draw of <SceneCanvas (jupyter_rfb) at 0x1f4ee0a82f0>> for DrawEvent

vispy WARNING Traceback (most recent call last):

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\threading.py", line 1014, in _bootstrap

self._bootstrap_inner()

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\threading.py", line 1043, in _bootstrap_inner

self.run()

File "C:\Users\almar\dev.venv\Lib\site-packages\ipykernel\subshell.py", line 38, in run

super().run()

File "C:\Users\almar\dev.venv\Lib\site-packages\ipykernel\thread.py", line 24, in run

self.io_loop.start()

File "C:\Users\almar\dev.venv\Lib\site-packages\tornado\platform\asyncio.py", line 211, in start

self.asyncio_loop.run_forever()

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\base_events.py", line 683, in run_forever

self._run_once()

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\base_events.py", line 2050, in _run_once

handle._run()

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\asyncio\events.py", line 89, in _run

self._context.run(self._callback, *self._args)

File "C:\Users\almar\dev\py\jupyter_rfb\jupyter_rfb\widget.py", line 289, in _rfb_maybe_draw

array = self.get_frame()

File "C:\Users\almar\dev\py\vispy\vispy\app\backends_jupyter_rfb.py", line 210, in get_frame

self._vispy_canvas.events.draw(region=None)

File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 453, in call

self._invoke_callback(cb, event)

File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 471, in _invoke_callback

_handle_exception(self.ignore_callback_errors,

<< caught exception here: >>

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl_gl2.py", line 518, in glCreateFramebuffer

nativefunc = glCreateFramebuffer._native

^^^^^^^^^^^^^^^^^^^^^^^^^^^

AttributeError: 'function' object has no attribute '_native'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl\gl2.py", line 70, in get_gl_func

func = getattr(lib, name)

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\ctypes_init.py", line 403, in getattr

func = self.getitem(name)

File "C:\Users\almar\AppData\Roaming\uv\python\cpython-3.13.7-windows-x86_64-none\Lib\ctypes_init.py", line 408, in getitem

func = self._FuncPtr((name_or_ordinal, self))

AttributeError: function 'glGenFramebuffers' not found
During handling of the above exception, another exception occurred:
Traceback (most recent call last):

File "C:\Users\almar\dev\py\vispy\vispy\util\event.py", line 469, in _invoke_callback

cb(event)

~~^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\context.py", line 172, in flush_commands

self.glir.flush(self.shared.parser)

~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 584, in flush

self._shared.flush(parser)

~~~~~~~~~~~~~~~~~~^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 506, in flush

parser.parse(self._filter(self.clear(), parser))

~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 824, in parse

self._parse(command)

~~~~~~~~~~~^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 764, in parse

self.objects[id] = klass(self, id)

~~~~~^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 899, in init

self.create()

~~~~~~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\glir.py", line 1752, in create

self._handle = gl.glCreateFramebuffer()

~~~~~~~~~~~~~~~~~~~~~~^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl_gl2.py", line 520, in glCreateFramebuffer

nativefunc = glCreateFramebuffer._native = _get_gl_func("glGenFramebuffers", None, (ctypes.c_int, ctypes.POINTER(ctypes.c_uint),))

~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "C:\Users\almar\dev\py\vispy\vispy\gloo\gl\gl2.py", line 85, in _get_gl_func

raise RuntimeError('Using %s with no OpenGL context.' % name)

RuntimeError: Using glGenFramebuffers with no OpenGL context.

vispy ERROR Invoking <bound method GLContext.flush_commands of <GLContext at 0x1f4f0711160>> for DrawEvent

BTW: I tried with jupyter_rfb 0.5.4, and there it crashes on glBindFrameBuffer too, but without the prior warnings.

[gselzer]

One thing that I will say is that somehow, I can run the ndv notebook example just fine with pyapp-kit/ndv#273. From a local copy of ndv on that branch

uv venv
uv pip install -e ".[vispy, jupyter]"

Then

uv run --no-sync jupyter notebook examples/notebook.ipynb

works fine, but

uv run --no-sync jupyter notebook <a copy of vispy1.ipynb>

throws the error 🙃

Been trying to figure out what the difference might be. I got nothing yet though 🙁

cc @tlambert03

[gselzer]

Okay, so the thing that ndv does that allows it to work on that branch is create a second canvas before showing the first. Here is the call that results in the main viewer being created, and here is the call that results in a second canvas. It's funny that apparently this was done to compensate for other vispy shenanigans

So, of course, this works on my machine🤯

from vispy import scene
from vispy.visuals.transforms import STTransform

canvas = scene.SceneCanvas(
    keys="interactive", bgcolor="white", size=(500, 400), show=True, resizable=True
)

view = canvas.central_widget.add_view()
view.camera = "arcball"

sphere1 = scene.visuals.Sphere(
    radius=1, method="latitude", parent=view.scene, edge_color="black"
)

sphere2 = scene.visuals.Sphere(
    radius=1, method="ico", parent=view.scene, edge_color="black"
)

sphere3 = scene.visuals.Sphere(
    radius=1,
    rows=10,
    cols=10,
    depth=10,
    method="cube",
    parent=view.scene,
    edge_color="black",
)

sphere1.transform = STTransform(translate=[-2.5, 0, 0])
sphere3.transform = STTransform(translate=[2.5, 0, 0])

view.camera.set_range(x=[-3, 3])
canvas.title = "Three spheres"
+ canvas2 = scene.SceneCanvas()
canvas

[almarklein]

Lol that works for me too 😢