项目启动时有报错，但是无法知道具体信息：
[root@Master new_project]# python3 manage.py runserver
Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
File "/usr/local/python3/lib/python3.8/threading.py", line 932, in _bootstrap_inner
self.run()
File "/usr/local/python3/lib/python3.8/threading.py", line 870, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/python3/lib/python3.8/site-packages/django/utils/autoreload.py", line 64, in wrapper
fn(*args, **kwargs)
File "/usr/local/python3/lib/python3.8/site-packages/django/core/management/commands/runserver.py", line 125, in inner_run
autoreload.raise_last_exception()
File "/usr/local/python3/lib/python3.8/site-packages/django/utils/autoreload.py", line 87, in raise_last_exception
raise _exception[1]
File "/usr/local/python3/lib/python3.8/site-packages/django/core/management/__init__.py", line 394, in execute
autoreload.check_errors(django.setup)()
File "/usr/local/python3/lib/python3.8/site-packages/django/utils/autoreload.py", line 64, in wrapper
fn(*args, **kwargs)
File "/usr/local/python3/lib/python3.8/site-packages/django/__init__.py", line 24, in setup
apps.populate(settings.INSTALLED_APPS)
File "/usr/local/python3/lib/python3.8/site-packages/django/apps/registry.py", line 84, in populate
raise RuntimeError("populate() isn't reentrant")
RuntimeError: populate() isn't reentrant
解决方法，把最后一行的报错文件的对应行数里面的内容raise RuntimeError("populate() isn't reentrant")替换成self.app_configs = {}，报错立显！
