Django 3 runserver command stops after login into admin page

[Alejandro Otero Ortiz de Cosca]

Description

The Django 3 development server halts when login into the admin page. The dev server (runserver) serving a blank (straight after running startproject) project responds fine to the welcome page and the admin login form page, but it crashes when redirecting after a successful login.

• The dev server starts without errors or warnings.
• All requests are responded correctly (base endpoint and admin login page).
• Login request seems to be processed correctly, client gets the 302 redirection to the admin page after login.
• Server stops working without printing any error.

Dev server output

Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
December 15, 2019 - 12:52:00
Django version 3.0, using settings 'admin_login_issue.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[15/Dec/2019 xx:xx:xx] "GET /admin/ HTTP/1.1" 302 0
[15/Dec/2019 xx:xx:xx] "GET /admin/login/?next=/admin/ HTTP/1.1" 200 1913
[15/Dec/2019 xx:xx:xx] "GET /static/admin/css/base.css HTTP/1.1" 304 0
[15/Dec/2019 xx:xx:xx] "GET /static/admin/css/login.css HTTP/1.1" 304 0
[15/Dec/2019 xx:xx:xx] "GET /static/admin/css/responsive.css HTTP/1.1" 304 0
[15/Dec/2019 xx:xx:xx] "GET /static/admin/css/fonts.css HTTP/1.1" 304 0
[15/Dec/2019 xx:xx:xx] "POST /admin/login/?next=/admin/ HTTP/1.1" 302 0

System description

• Python 3.7.0
• Django 3.0
• Mac OS Mojave 10.14.6

Reproduction steps

• Create virtualenv
• Install Django==3.0
• Create django project

django-admin startproject admin_login_issue

• Run migrations

python manage.py migrate

• Create superuser

python manage.py createsuperuser

• Start development server

python manage.py runserver

• Access ​http://127.0.0.1:8000/admin/
• Login with your superuser. You should get an error connecting to the server.
• Check the running server. It should not be running.

[Alejandro Otero Ortiz de Cosca]

I have created a new virtualenv with Python 3.8 and the client can access the admin portal but the server log shows an exception:

[15/Dec/2019 13:20:54] "GET /admin/ HTTP/1.1" 302 0
[15/Dec/2019 13:20:54] "GET /admin/login/?next=/admin/ HTTP/1.1" 200 1913
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 52778)
Traceback (most recent call last):
  File "/Users/aotero/.pyenv/versions/3.8.0/lib/python3.8/socketserver.py", line 650, in process_request_thread
    self.finish_request(request, client_address)
  File "/Users/aotero/.pyenv/versions/3.8.0/lib/python3.8/socketserver.py", line 360, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/Users/aotero/.pyenv/versions/3.8.0/lib/python3.8/socketserver.py", line 720, in __init__
    self.handle()
  File "/Users/aotero/.pyenv/versions/3.8.0/envs/admin_login_issue-3.8.0/lib/python3.8/site-packages/django/core/servers/basehttp.py", line 174, in handle
    self.handle_one_request()
  File "/Users/aotero/.pyenv/versions/3.8.0/envs/admin_login_issue-3.8.0/lib/python3.8/site-packages/django/core/servers/basehttp.py", line 182, in handle_one_request
    self.raw_requestline = self.rfile.readline(65537)
  File "/Users/aotero/.pyenv/versions/3.8.0/lib/python3.8/socket.py", line 669, in readinto
    return self._sock.recv_into(b)
ConnectionResetError: [Errno 54] Connection reset by peer
----------------------------------------
[15/Dec/2019 13:20:58] "POST /admin/login/?next=/admin/ HTTP/1.1" 302 0
[15/Dec/2019 13:20:58] "GET /admin/ HTTP/1.1" 200 3043
[15/Dec/2019 13:20:58] "GET /static/admin/css/dashboard.css HTTP/1.1" 304 0
[15/Dec/2019 13:20:58] "GET /static/admin/img/icon-addlink.svg HTTP/1.1" 304 0
[15/Dec/2019 13:20:58] "GET /static/admin/img/icon-changelink.svg HTTP/1.1" 304 0

[Baptiste Mispelon]

Hi,

This seems like a duplicated of issue #31067 which should be fixed by upgrading your Python version to the latest supported version in the 3.7 branch (3.7.5 I think).

Please reopen if that's not the case, thanks.