Matplotlib with interactive mode creates empty figure

[anton-br]

ALL software version info

General:
Ubuntu 22.04.2 LTS
python 3.11.3

library versions:
bokeh==3.3.4
ipympl==0.9.3
ipykernel==6.29.3
ipyleaflet==0.18.2
ipympl==0.9.3
ipython==8.22.1
ipython_genutils==0.2.0
ipywidgets==8.1.2
ipywidgets-bokeh==1.5.0
jupyterlab==4.1.2
jupyterlab_pygments==0.3.0
jupyterlab_server==2.25.3
jupyterlab_widgets==3.0.10
matplotlib==3.8.3
panel==1.3.8

browser:
Chrome 122.0.6261.94

I am trying to reproduce tutorials from here. Everything works fine untill Using the interactive Matplotlib backend section.
Either in jupyter lab or by panel serve I'm receiving the same result: text - Figure with small part of the toolbar.

If summarize, code is the following:

import numpy as np
import panel as pn

pn.extension('ipywidgets')
from matplotlib.figure import Figure

fig = Figure(figsize=(8, 6))
ax = fig.add_subplot(111)

dx, dy = 0.05, 0.05

# generate 2 2d grids for the x & y bounds
y, x = np.mgrid[slice(1, 5 + dy, dy),
                slice(1, 5 + dx, dx)]

z = np.sin(x)**10 + np.cos(10 + y*x) * np.cos(x)

cf = ax.contourf(x + dx/2., y + dy/2., z)
fig.colorbar(cf, ax=ax)

pn.pane.Matplotlib(fig, interactive=True, dpi=72)

My output:

JupyterLab:

When hovering the mouse over the Figure text:

Same if start with panel serve (I've only added .servable() to pn.pane.Matplotlib to make it work):

Acually, in the tutorials we can see the same output right now:

Console output

In bash:

In browser:

Some elements of ipywidgets_bokeh are not found. However, googling the error gives no result.

I've tried to add pn.extension(sizing_mode="stretch_width") as was mentioned here but it did not work.

• I may be interested in making a pull request to address this