[BUG] Flask 2.2.0 unbound_message error.

[ikoch1978]

Describe your context
Environment currently running in Docker, with the following Dockerfiles:

Our ubuntu:latest dockerfile:

FROM ubuntu:20.04
ENV DEBIAN_FRONTEND="noninteractive"
LC_ALL="en_US.UTF-8"
LANG="en_US.UTF-8"
LANGUAGE="en_US.UTF-8"
RUN apt-get update &&
apt-get upgrade -y &&
apt-get install -y ca-certificates tzdata locales &&
update-ca-certificates -f &&
rm /etc/timezone &&
rm /etc/localtime &&
echo "Europe/Berlin" | tee /etc/timezone &&
ln -s /usr/share/zoneinfo/Europe/Berlin /etc/localtime &&
dpkg-reconfigure --frontend noninteractive tzdata &&
locale-gen en_US.UTF-8 &&
echo "LC_ALL=en_US.UTF8" > /etc/default/locale &&
echo "LANG=en_US.UTF8" >> /etc/default/locale &&
echo "LC_CTYPE=en_US.UTF8" >> /etc/default/locale &&
echo "LC_COLLATE=en_US.UTF8" >> /etc/default/locale &&
chmod 0755 /etc/default/locale

Our python:latest dockerfile:

FROM **/base-images/ubuntu:latest
ADD pip.conf /etc/pip.conf
ENV REQUESTS_CA_BUNDLE="/etc/ssl/certs/ca-certificates.crt"
PIP_DEFAULT_TIMEOUT=120
RUN apt-get update &&
apt-get install -y build-essential zlib1g-dev libncurses5-dev libgdbm-dev libnss3-dev libssl-dev libreadline-dev libffi-dev libsqlite3-dev wget libbz2-dev curl &&
mkdir /tempdir &&
cd /tempdir &&
curl https://www.python.org/ftp/python/3.10.2/Python-3.10.2.tgz -o python.tgz &&
tar -xvzf python.tgz &&
cd Python-3.10.2 &&
./configure --enable-optimizations &&
make &&
make install &&
cd &&
rm -rf /tempdir &&
python3 -m pip install --upgrade pip &&
pip3 install requests &&
apt-get remove -y curl wget
USER app
WORKDIR /app
ENV PATH="${PATH}:/app/.local/bin/"
CMD ["/usr/bin/python3"]

Our dash:latest dockerfile:

FROM **/base-images/python:latest
USER root
RUN pip3 install dash dash-renderer dash-html-components dash-core-components plotly gunicorn Flask
EXPOSE 5000
USER app
COPY *.py /app/
CMD ["gunicorn", "--workers", "1", "--bind", "0.0.0.0:5000", "--timeout", "100000", "--max-requests", "20", "--access-logfile", "-", "--error-logfile", "-", "--capture-output", "application:server"]

Our docker file:

FROM **/base-images/dash:latest

EXPOSE 5000
CMD ["gunicorn", "-w", "1", "-b", "0.0.0.0:5000", "-t", "0", "--max-requests", "0", "--access-logfile", "-", "--error-logfile", "-", "--capture-output", "index:server"]
USER root
COPY requirements.txt /tmp/
RUN pip3 install -r /tmp/requirements.txt &&
rm /tmp/requirements.txt
USER app
COPY . /app

• replace the result of pip list | grep dash below

dash                                  2.0.0
dash-bootstrap-components             0.11.4rc3
dash-core-components                  2.0.0
dash-html-components                  2.0.0
dash-table                            5.0.0

Describe the bug

I am not able to start my app, I get the following error:

[2022-08-08 11:24:34 +0200] [1] [INFO] Starting gunicorn 20.0.4
[2022-08-08 11:24:34 +0200] [1] [INFO] Listening at: http://0.0.0.0:5000 (1)
[2022-08-08 11:24:34 +0200] [1] [INFO] Using worker: sync
[2022-08-08 11:24:34 +0200] [8] [INFO] Booting worker with pid: 8
[2022-08-08 11:24:34 +0200] [9] [INFO] Booting worker with pid: 9
[2022-08-08 11:24:34 +0200] [10] [INFO] Booting worker with pid: 10
[2022-08-08 11:24:34 +0200] [8] [ERROR] Exception in worker process
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 583, in spawn_worker
worker.init_process()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 119, in init_process
self.load_wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 144, in load_wsgi
self.wsgi = self.app.wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/base.py", line 67, in wsgi
self.callable = self.load()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 49, in load
return self.load_wsgiapp()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 39, in load_wsgiapp
return util.import_app(self.app_uri)
File "/usr/local/lib/python3.8/dist-packages/gunicorn/util.py", line 358, in import_app
mod = importlib.import_module(module)
File "/usr/lib/python3.8/importlib/init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1014, in _gcd_import
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "", line 848, in exec_module
File "", line 219, in _call_with_frames_removed
File "/app/index.py", line 1, in
import dash_bootstrap_components as dbc
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/init.py", line 5, in
from dash_bootstrap_components import _components, icons, themes
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/init.py", line 1, in
from .Accordion import Accordion
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/Accordion.py", line 3, in
from dash.development.base_component import Component, _explicitize_args
File "/usr/local/lib/python3.8/dist-packages/dash/init.py", line 5, in
from .dependencies import ( # noqa: F401,E402
File "/usr/local/lib/python3.8/dist-packages/dash/dependencies.py", line 4, in
from ._validate import validate_callback
File "/usr/local/lib/python3.8/dist-packages/dash/_validate.py", line 5, in
import flask
File "/usr/local/lib/python3.8/dist-packages/flask/init.py", line 4, in
from . import json as json
File "/usr/local/lib/python3.8/dist-packages/flask/json/init.py", line 8, in
from ..globals import current_app
File "/usr/local/lib/python3.8/dist-packages/flask/globals.py", line 56, in
app_ctx: "AppContext" = LocalProxy( # type: ignore[assignment]
TypeError: init() got an unexpected keyword argument 'unbound_message'
[2022-08-08 11:24:34 +0200] [8] [INFO] Worker exiting (pid: 8)
[2022-08-08 11:24:34 +0200] [9] [ERROR] Exception in worker process
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 583, in spawn_worker
worker.init_process()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 119, in init_process
self.load_wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 144, in load_wsgi
self.wsgi = self.app.wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/base.py", line 67, in wsgi
self.callable = self.load()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 49, in load
return self.load_wsgiapp()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 39, in load_wsgiapp
return util.import_app(self.app_uri)
File "/usr/local/lib/python3.8/dist-packages/gunicorn/util.py", line 358, in import_app
mod = importlib.import_module(module)
File "/usr/lib/python3.8/importlib/init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1014, in _gcd_import
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "", line 848, in exec_module
File "", line 219, in _call_with_frames_removed
File "/app/index.py", line 1, in
import dash_bootstrap_components as dbc
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/init.py", line 5, in
from dash_bootstrap_components import _components, icons, themes
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/init.py", line 1, in
from .Accordion import Accordion
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/Accordion.py", line 3, in
from dash.development.base_component import Component, _explicitize_args
File "/usr/local/lib/python3.8/dist-packages/dash/init.py", line 5, in
from .dependencies import ( # noqa: F401,E402
File "/usr/local/lib/python3.8/dist-packages/dash/dependencies.py", line 4, in
from ._validate import validate_callback
File "/usr/local/lib/python3.8/dist-packages/dash/_validate.py", line 5, in
import flask
File "/usr/local/lib/python3.8/dist-packages/flask/init.py", line 4, in
from . import json as json
File "/usr/local/lib/python3.8/dist-packages/flask/json/init.py", line 8, in
from ..globals import current_app
File "/usr/local/lib/python3.8/dist-packages/flask/globals.py", line 56, in
app_ctx: "AppContext" = LocalProxy( # type: ignore[assignment]
TypeError: init() got an unexpected keyword argument 'unbound_message'
[2022-08-08 11:24:34 +0200] [9] [INFO] Worker exiting (pid: 9)
[2022-08-08 11:24:34 +0200] [10] [ERROR] Exception in worker process
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 583, in spawn_worker
worker.init_process()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 119, in init_process
self.load_wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/workers/base.py", line 144, in load_wsgi
self.wsgi = self.app.wsgi()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/base.py", line 67, in wsgi
self.callable = self.load()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 49, in load
return self.load_wsgiapp()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/app/wsgiapp.py", line 39, in load_wsgiapp
return util.import_app(self.app_uri)
File "/usr/local/lib/python3.8/dist-packages/gunicorn/util.py", line 358, in import_app
mod = importlib.import_module(module)
File "/usr/lib/python3.8/importlib/init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1014, in _gcd_import
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "", line 848, in exec_module
File "", line 219, in _call_with_frames_removed
File "/app/index.py", line 1, in
import dash_bootstrap_components as dbc
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/init.py", line 5, in
from dash_bootstrap_components import _components, icons, themes
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/init.py", line 1, in
from .Accordion import Accordion
File "/usr/local/lib/python3.8/dist-packages/dash_bootstrap_components/_components/Accordion.py", line 3, in
from dash.development.base_component import Component, _explicitize_args
File "/usr/local/lib/python3.8/dist-packages/dash/init.py", line 5, in
from .dependencies import ( # noqa: F401,E402
File "/usr/local/lib/python3.8/dist-packages/dash/dependencies.py", line 4, in
from ._validate import validate_callback
File "/usr/local/lib/python3.8/dist-packages/dash/_validate.py", line 5, in
import flask
File "/usr/local/lib/python3.8/dist-packages/flask/init.py", line 4, in
from . import json as json
File "/usr/local/lib/python3.8/dist-packages/flask/json/init.py", line 8, in
from ..globals import current_app
File "/usr/local/lib/python3.8/dist-packages/flask/globals.py", line 56, in
app_ctx: "AppContext" = LocalProxy( # type: ignore[assignment]
TypeError: init() got an unexpected keyword argument 'unbound_message'
[2022-08-08 11:24:34 +0200] [10] [INFO] Worker exiting (pid: 10)
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 202, in run
self.manage_workers()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 545, in manage_workers
self.spawn_workers()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 617, in spawn_workers
time.sleep(0.1 * random.random())
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 242, in handle_chld
self.reap_workers()
File "/usr/local/lib/python3.8/dist-packages/gunicorn/arbiter.py", line 525, in reap_workers
raise HaltServer(reason, self.WORKER_BOOT_ERROR)
gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>

Expected behavior

Starting of the server and listening to port in localhost.

Thank you very much for the help!

[T4rk1n]

This line is the error:

got an unexpected keyword argument 'unbound_message'

Related to flask 2.2.0, you can pin earlier version of flask to fix the issue in the meantime.

[alexcjohnson]

Generally though people are able to use Dash with Flask 2.2 (eg #2177) - so is there something else required to generate this problem, some other pinned dependency?

[T4rk1n]

It's werkzeug version mismatch, flask 2.2.x needs werkzeug 2.2.x

[hannahker]

I've also had a report of this error coming up with a slightly different stack trace:

“Traceback (most recent call last):
  File "/workspace/app.py", line 2, in <module>
    import dash
  File "/app/.heroku/python/lib/python3.9/site-packages/dash/__init__.py", line 5, in <module>
    from .dash import Dash, no_update  # noqa: F401,E402
  File "/app/.heroku/python/lib/python3.9/site-packages/dash/dash.py", line 17, in <module>
    import flask
  File "/app/.heroku/python/lib/python3.9/site-packages/flask/__init__.py", line 4, in <module>
    from . import json as json
  File "/app/.heroku/python/lib/python3.9/site-packages/flask/json/__init__.py", line 8, in <module>
    from ..globals import current_app
  File "/app/.heroku/python/lib/python3.9/site-packages/flask/globals.py", line 56, in <module>
    app_ctx: "AppContext" = LocalProxy(  # type: ignore[assignment]
TypeError: __init__() got an unexpected keyword argument 'unbound_message'”

Downgrading Flask resolved this. @T4rk1n do you think this is the same version mismatch problem?

[T4rk1n]

@hannahker Yes, this happen when flask 2.2.x is installed but not werkzeug, possibly because werkzeug version was locked in requirements.txt but not flask