Arch Linux

Description: After updating to the version in testing (10.0.1-1), running any pip command gives

➜ pip
Traceback (most recent call last):
File "/usr/bin/pip", line 11, in <module>
load_entry_point('pip==10.0.1', 'console_scripts', 'pip')()
File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 480, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 2691, in load_entry_point
return ep.load()
File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 2322, in load
return self.resolve()
File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 2328, in resolve
module = __import__(self.module_name, fromlist=['__name__'], level=0)
File "/usr/lib/python3.6/site-packages/pip/_internal/__init__.py", line 42, in <module>
from pip._internal import cmdoptions
File "/usr/lib/python3.6/site-packages/pip/_internal/cmdoptions.py", line 16, in <module>
from pip._internal.index import (
File "/usr/lib/python3.6/site-packages/pip/_internal/index.py", line 20, in <module>
from pip._vendor.requests.exceptions import SSLError
ModuleNotFoundError: No module named 'pip._vendor.requests.exceptions'

Steps to reproduce: Just update and run pip.