我想使用pipenv，但是有两个软件包对我造成了问题？ 在过去2年多的时间里，似乎有几篇类似的帖子，但我找不到真正的答案。 我获得了最新版本的pipenv（2020.6.2），并要求安装cffi（1.14.1）的最新软件包。
enter code here（请参见下面的示例）
＃pipenv版本
pipenv --version pipenv，版本2020.6.2
＃在具有pip3一切的pipenv之外，一切正常
pip3 install cffi == 1.14.1
Requirement already satisfied: cffi==1.14.1 in /home/john/.local/lib/python3.8/site-packages (1.14.1)
Requirement already satisfied: pycparser in /home/john/.local/lib/python3.8/site-packages (from cffi==1.14.1) (2.20)
问题示例：
pipenv install cffi == 1.14.1
Error: An error occurred while installing cffi==1.14.1!
Error text:
Traceback (most recent call last):
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/bin/pip", line 5, in <module>
from pip._internal.cli.main import main
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/cli/main.py", line 10, in <module>
from pip._internal.cli.autocompletion import autocomplete
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/cli/autocompletion.py", line 9, in <module>
from pip._internal.cli.main_parser import create_main_parser
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/cli/main_parser.py", line 7, in <module>
from pip._internal.cli import cmdoptions
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/cli/cmdoptions.py", line 25, in <module>
from pip._internal.locations import USER_CACHE_DIR, get_src_prefix
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/locations.py", line 19, in <module>
from pip._internal.utils import appdirs
File "/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_internal/utils/appdirs.py", line 13, in <module>
from pip._vendor import appdirs as _appdirs
ImportError: cannot import name 'appdirs' from 'pip._vendor' (/home/john/.local/share/virtualenvs/06-Login-Auth-HAdzgzLT/lib/python3.8/site-packages/pip/_vendor/__init__.py)