TQDM.ipynb reference raises exception: AttributeError: Column.value property descriptor does not exist

[MarcSkovMadsen]

I'm on Panel 0.12.0, Param 1.11.1, Bokeh: 2.3.3

If I run the TQDM.ipynb reference notebook top to bottom and click one of the buttons I get a AttributeError: Column.value property descriptor does not exist error.

[MarcSkovMadsen]

You can replicate the problem using this simple script

import time

import panel as pn

from panel.widgets import Tqdm

pn.extension()

tqdm = Tqdm()

def run_loop(*events, timeout=0.2):
    for i in tqdm(range(0,10), desc="My loop bar", leave=True, colour='#666666'):
        time.sleep(timeout)

run_loop(timeout=0.01)

button = pn.widgets.Button(name="Run Loop", button_type="success")
button.on_click(run_loop)
pn.Row(button, tqdm).servable()

[MarcSkovMadsen]

I've tried to identify the cause and understand how to fix this without success.

I can see it tries to set the value on a Column which does not make sense. But why I don't understand. I suspect something changed in reactive.py since I implemented TQDM and tested. But I cannot find out what.

I will need your help @philippjfr to fix this.

[philippjfr]

Got a fix, will push out a 0.12.1 in the coming days.