SyntaxError when testing pootle with runserver command

[tasso85]

This test is a consequence of #6917, for which I tried installing in a clean environment with MySQL 5.7

Steps to reproduce:

• install pootle on MySQL 5.7
• run pootle for quick test with pootle runserver --insecure 0.0.0.0:8000

Results (Expected/Actual):

I would expect Pootle homepage to open, instead I see

A server error occurred.  Please contact the administrator.

The logs of the runserver command says:

Traceback (most recent call last):
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/core/handlers/base.py", line 215, in _get_response
    response = response.render()
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/response.py", line 109, in render
    self.content = self.rendered_content
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/response.py", line 84, in rendered_content
    template = self.resolve_template(self.template_name)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/response.py", line 66, in resolve_template
    return select_template(template, using=self.using)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/loader.py", line 44, in select_template
    engines = _engine_list(using)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/loader.py", line 72, in _engine_list
    return engines.all() if using is None else [engines[using]]
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/utils.py", line 89, in all
    return [self[alias] for alias in self]
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/utils.py", line 80, in __getitem__
    engine = engine_cls(params)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/backends/django.py", line 30, in __init__
    options['libraries'] = self.get_templatetag_libraries(libraries)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/backends/django.py", line 48, in get_templatetag_libraries
    libraries = get_installed_libraries()
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/backends/django.py", line 113, in get_installed_libraries
    for name in get_package_libraries(pkg):
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/django/template/backends/django.py", line 126, in get_package_libraries
    module = import_module(entry[1])
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/statici18n/templatetags/statici18n.py", line 13, in <module>
    from statici18n.conf import settings
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/statici18n/conf.py", line 3, in <module>
    from appconf import AppConf
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/appconf/__init__.py", line 1, in <module>
    from .base import AppConf  # noqa
  File "/home/mtassinari/pootle/env/lib/python2.7/site-packages/appconf/base.py", line 107
    class AppConf(metaclass=AppConfMetaClass):
                           ^
SyntaxError: invalid syntax

Environment (i.e. 'pootle --version', DB, OS, Browser):

Ubuntu 20.04
Pootle 2.8.2 (Django 1.10.8, Translate Toolkit 2.2.5)
Python 2.7.18
mysql Ver 14.14 Distrib 5.7.38, for Linux (x86_64) using EditLine wrapper

[anoek]

FTR I worked around this error by downgrading django-appconf to 1.0.2 with pip install django-appconf==1.0.2. This was the last known working version for my setup, I didn't try other versions to find out when it broke.