Multipaging with custom 404 page and pages_folder does not work as expected

Dash Python
1

I set up an example multipage app, using pages_folder.

backend
---> __init__.py
---> applcation.py
pages
---> home_page.py
---> not_found_404.py
---> page2.py
run.py

backend/init.py:

from .application import app

backend/application.py:

from dash import Dash, html, dcc
import dash

pages_folder =  '../pages'

app = Dash(__name__, 
           use_pages=True,
           pages_folder=pages_folder)

app.layout = html.Div([
    dash.page_container
])

pages/home_page.py:

import dash
from dash import html, dcc

dash.register_page(__name__, path='/')

layout = html.Div('Home page')

pages/page2.py:

import dash
from dash import html, dcc, callback, Input, Output

dash.register_page(__name__)

layout = html.Div('Page2!!')

pages/not_found_404.py:

from dash import html
import dash

dash.register_page(__name__)

layout = html.H1("This is a custom 404 page that does not work")

run.py:

from backend import app


if __name__ == '__main__':
    app.run_server(debug=True)

When I move the dash app in such a way, that I do not need to set path_pages, it does work as expected.
I was thinking, that the relative path in path_pages could be responsible for that behavior.
Weirdly, when setting pages_folder=os.getcwd() + '/pages', I get an error message with

A folder called … does not exist.

While when trying to set assets_folder=os.getcwd + '/custom_assets', it works.
This means, pages_folder and assets_folder work differently. The former can only handle relative paths while the latter can also work with absolute ones? This seems odd to me

This seems to be connected to Bug - cannot register not_found_404 with dash.register_page() - #6 by jinnyzor

Should I open a bug report in git?

2

Try updating to the latest Dash. This is a known bug that was fixed in Dash 2.7.0.

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