Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#32202 closed Bug (fixed)

django-admin runserver and get_child_arguments() crashes on Windows and Python < 3.8.

Reported by: andrey-zotov Owned by: Carlton Gibson
Component: Core (Management commands) Version: 3.1
Severity: Release blocker Keywords:
Cc: Carlton Gibson, Tom Forbes Triage Stage: Ready for checkin
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no


"django-admin runserver" fails with the following error:

Traceback (most recent call last):
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\someone\AppData\Local\Programs\Python\Python37\Scripts\django-admin.exe\", line 7, in <module>
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\", line 401, in execute_from_command_line
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\", line 395, in execute
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\commands\", line 61, in execute
    super().execute(*args, **options)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\", line 371, in execute
    output = self.handle(*args, **options)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\commands\", line 96, in handle**options)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\core\management\commands\", line 103, in run
    autoreload.run_with_reloader(self.inner_run, **options)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\utils\", line 616, in run_with_reloader
    exit_code = restart_with_reloader()
  File "c:\users\someone\appdata\local\programs\python\python37\lib\site-packages\django\utils\", line 244, in restart_with_reloader
    p =, env=new_environ, close_fds=False)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 488, in run
    with Popen(*popenargs, **kwargs) as process:
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 800, in __init__
    restore_signals, start_new_session)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 1148, in _execute_child
    args = list2cmdline(args)
  File "c:\users\someone\appdata\local\programs\python\python37\lib\", line 555, in list2cmdline
    needquote = (" " in arg) or ("\t" in arg) or not arg
TypeError: argument of type 'WindowsPath' is not iterable

Windows 10
Python: 3.7.6
Django: 3.1.3

Steps to reproduce:

django-admin startproject mysite
set PYTHONPATH=<thelocaldir>
django-admin runserver --settings=mysite.settings

Apparently django.utils.autoreload.get_child_arguments returns WindowsPath("C:\Users\someone\AppData\Local\Programs\Python\Python37\Scripts\django-admin.exe") as the first argument,
and subprocess.Popen expects a string and is not able to use Path.

The following monkey-patch fixes the error:

def get_child_arguments_override():
    args = autoreload._get_child_arguments()
    for i, arg in enumerate(args):
        if isinstance(arg, Path):
            args[i] = str(arg)
    return args

autoreload._get_child_arguments = autoreload.get_child_arguments
autoreload.get_child_arguments = get_child_arguments_override

Change History (6)

comment:1 by Mariusz Felisiak, 4 years ago

Cc: Carlton Gibson Tom Forbes added
Severity: NormalRelease blocker
Summary: django-admin runserver and get_child_argumentsdjango-admin runserver and get_child_arguments() crashes on Windows and Python < 3.8.
Triage Stage: UnreviewedAccepted

Tentatively accepted, I cannot check this on Windows, but it looks like a regression in 8a902b7ee622ada258d15fb122092c1f02b82698.'s args parameter accepts path-like objects on Windows since Python 3.8 (see similar issue for dbshell, #31076).

comment:2 by Carlton Gibson, 4 years ago

Owner: changed from nobody to Carlton Gibson
Status: newassigned

comment:3 by Carlton Gibson, 4 years ago

Has patch: set

comment:4 by Mariusz Felisiak, 4 years ago

Triage Stage: AcceptedReady for checkin

comment:5 by GitHub <noreply@…>, 4 years ago

Resolution: fixed
Status: assignedclosed

In ead37dfb:

Fixed #32202 -- Fixed autoreloader argument generation for Windows with Python 3.7-.

comment:6 by Carlton Gibson <carlton.gibson@…>, 4 years ago

In 012822c7:

[3.1.x] Fixed #32202 -- Fixed autoreloader argument generation for Windows with Python 3.7-.

Backport of ead37dfb580136cc27dbd487a1f1ad90c9235d15 from master

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