`.grid` method on `Holomap` not working correctly

[bertcoerver]

ALL software version info

(this library, plus any other relevant software, e.g. bokeh, python, notebook, OS, browser, etc should be added within the dropdown below.)

Software Version Info

holoviews == 1.22.1
bokeh == 3.8.1
python == 3.14.2

Description of expected behavior and the observed behavior

I've got a hv.Holomap that I want to overlay in one key-dimension and then grid along another key-dimension. However, the gridding step results in an empty graph (and the the charts do not line up correctly with the axis).

Complete, minimal, self-contained example code that reproduces the issue

import pickle
import holoviews as hv
hv.extension("bokeh")

with open("test_holomap.txt", "rb") as file:
    hm: hv.HoloMap = pickle.load(file)

hm = hm.overlay("model")

# hm.layout("class") # NOTE: this works.
hm.grid("class") # NOTE: this does not work.

Stack traceback and/or browser JavaScript console output

Screenshots or screencasts of the bug in action

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

[holovizbot]

This issue has been mentioned on HoloViz Discourse. There might be relevant details there:

https://discourse.holoviz.org/t/converting-holomap-into-gridspace-troubles/9043/3

[hoxbro]

This is a duplicate of #5438.

Also removed the link to pickle, as it is not safe to open it, as it can run arbitrary code. See https://docs.python.org/3/library/pickle.html for more information.

[bertcoerver]

Isnt #5438 only part of the problem here? I don't think the individual plots there are empty?

[hoxbro]

Didn't notice that. Can you make an example without using pickle?