daemonize.py: unbuffered text IO error (python3)

[alex01@…]

When trying to run fcgi server I get "ValueError: can't have unbuffered text I/O"

My python version and django version:

$ python --version
Python 3.2.3

>>> django.get_version()
'1.7.dev20130726184538'

Can't start server:
(virtenv02)jsmith@thinkpad01:~/virtenv02/mysite$ python manage.py runfcgi host=127.0.0.1 port=8100
Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/jsmith/virtenv02/django-trunk/django/core/management/__init__.py", line 397, in execute_from_command_line
    utility.execute()
  File "/home/jsmith/virtenv02/django-trunk/django/core/management/__init__.py", line 390, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/jsmith/virtenv02/django-trunk/django/core/management/base.py", line 240, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/home/jsmith/virtenv02/django-trunk/django/core/management/base.py", line 283, in execute
    output = self.handle(*args, **options)
  File "/home/jsmith/virtenv02/django-trunk/django/core/management/commands/runfcgi.py", line 22, in handle
    runfastcgi(args)
  File "/home/jsmith/virtenv02/django-trunk/django/core/servers/fastcgi.py", line 176, in runfastcgi
    become_daemon(our_home_dir=options["workdir"], **daemon_kwargs)
  File "/home/jsmith/virtenv02/django-trunk/django/utils/daemonize.py", line 28, in become_daemon
    so = open(out_log, 'a+', 0)
ValueError: can't have unbuffered text I/O

Server starts successfully and works if I give it daemonize=False option:
(virtenv02)jsmith@thinkpad01:~/virtenv02/mysite$ python manage.py runfcgi host=127.0.0.1 port=8100 daemonize=False

As far as I understand, this issue is specific to python3 and is related to changes in open function introduced in pep-3116

Alex

[Claude Paroz]

Unfortunately, this is old untested code. I wonder if the solution would be to simply forget the 0 argument (unbuffered) of the open call. Maybe someone more knowledgeable about buffered/unbuffered output may chime in to enlighten us?