KeyError: 'WERKZEUG_SERVER_FD' when running runserver_plus with noreload flag
Author: AutomatikCreated Sep 10, 2024Updated Mar 7, 2026
I encountered an issue when trying to run my Django server using runserver_plus with noreload flag from django-extensions in a project created via cookiecutter-django.
The command I used is:
python manage.py runserver_plus 0.0.0.0:8000 --noreload
This raises the following error: KeyError: 'WERKZEUG_SERVER_FD'
Full traceback
Traceback (most recent call last):
File "/home/path/to/my/project/manage.py", line 31, in <module>
execute_from_command_line(sys.argv)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
utility.execute()
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django/core/management/__init__.py", line 436, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django/core/management/base.py", line 412, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django/core/management/base.py", line 458, in execute
output = self.handle(*args, **options)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django_extensions/management/utils.py", line 62, in inner
ret = func(self, *args, **kwargs)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django_extensions/management/commands/runserver_plus.py", line 338, in handle
self.inner_run(options)
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/django_extensions/management/commands/runserver_plus.py", line 459, in inner_run
run_simple(
File "/home/user/.venv/myvenv/lib/python3.10/site-packages/werkzeug/serving.py", line 1075, in run_simple
fd = int(os.environ["WERKZEUG_SERVER_FD"])
File "/usr/lib/python3.10/os.py", line 680, in __getitem__
raise KeyError(key) from None
KeyError: 'WERKZEUG_SERVER_FD'
And these are my requirements: base.txt
python-slugify==8.0.1 # https://github.com/un33k/python-slugify
Pillow==10.2.0 # https://github.com/python-pillow/Pillow
argon2-cffi==23.1.0 # https://github.com/hynek/argon2_cffi
# redis==5.0.1 # https://github.com/redis/redis-py
# hiredis==2.3.2 # https://github.com/redis/hiredis-py
# celery==5.3.6 # pyup: < 6.0 # https://github.com/celery/celery
# django-celery-beat==2.5.0 # https://github.com/celery/django-celery-beat
# flower==2.0.1 # https://github.com/mher/flower
# Django
# ------------------------------------------------------------------------------
django==4.2.9 # pyup: < 5.0 # https://www.djangoproject.com/
django-environ==0.11.2 # https://github.com/joke2k/django-environ
django-model-utils==4.3.1 # https://github.com/jazzband/django-model-utils
django-allauth==0.59.0 # https://github.com/pennersr/django-allauth
django-crispy-forms==2.1 # https://github.com/django-crispy-forms/django-crispy-forms
crispy-bootstrap5==2023.10 # https://github.com/django-crispy-forms/crispy-bootstrap5
django-redis==5.4.0 # https://github.com/jazzband/django-redis
# Django REST Framework
djangorestframework==3.14.0 # https://github.com/encode/django-rest-framework
django-cors-headers==4.3.1 # https://github.com/adamchainz/django-cors-headers
# DRF-spectacular for api documentation
drf-spectacular==0.27.0 # https://github.com/tfranzel/drf-spectacular
django-filter==23.5 # https://django-filter.readthedocs.io/en/latest/index.html
django-admin-rangefilter==0.12.0 # https://github.com/silentsokolov/django-admin-rangefilter
dj-rest-auth==5.0.2 # https://github.com/iMerica/dj-rest-auth
numpy==1.26.4
opencv-python-headless==4.9.0.80local.txt
-r base.txt
Werkzeug[watchdog]==3.0.1 # https://github.com/pallets/werkzeug
ipdb==0.13.13 # https://github.com/gotcha/ipdb
psycopg[c]==3.1.16 # https://github.com/psycopg/psycopg
watchfiles==0.21.0 # https://github.com/samuelcolvin/watchfiles
toml==0.10.2 # per usare tomllib in python 3.10
# Testing
# ------------------------------------------------------------------------------
mypy==1.7.1 # https://github.com/python/mypy
django-stubs[compatible-mypy]==4.2.7 # https://github.com/typeddjango/django-stubs
pytest==7.4.4 # https://github.com/pytest-dev/pytest
pytest-sugar==0.9.7 # https://github.com/Frozenball/pytest-sugar
djangorestframework-stubs[compatible-mypy]==3.14.5 # https://github.com/typeddjango/djangorestframework-stubs
# Documentation
# ------------------------------------------------------------------------------
sphinx==7.2.6 # https://github.com/sphinx-doc/sphinx
sphinx-autobuild==2021.3.14 # https://github.com/GaretJax/sphinx-autobuild
# Code quality
# ------------------------------------------------------------------------------
flake8==7.0.0 # https://github.com/PyCQA/flake8
flake8-isort==6.1.1 # https://github.com/gforcada/flake8-isort
coverage==7.4.0 # https://github.com/nedbat/coveragepy
black==23.12.1 # https://github.com/psf/black
djlint==1.34.1 # https://github.com/Riverside-Healthcare/djLint
pylint-django==2.5.5 # https://github.com/PyCQA/pylint-django
# pylint-celery==0.3 # https://github.com/PyCQA/pylint-celery
pre-commit==3.6.0 # https://github.com/pre-commit/pre-commit
# Django
# ------------------------------------------------------------------------------
factory-boy==3.3.0 # https://github.com/FactoryBoy/factory_boy
django-debug-toolbar==4.2.0 # https://github.com/jazzband/django-debug-toolbar
django-extensions==3.2.3 # https://github.com/django-extensions/django-extensions
django-coverage-plugin==3.1.0 # https://github.com/nedbat/django_coverage_plugin
pytest-django==4.7.0 # https://github.com/pytest-dev/pytest-django
# Diagrams
# pygraphviz==1.12
pyparsing==3.1.1
pydot==2.0.0
Source: django-extensions/django-extensions