我正在尝试设置一个虚拟环境：
$ python3 -m venv cv2
但在尝试时，我遇到了这个异常：
Traceback (most recent call last):
File "/usr/lib/python3.6/runpy.py", line 183, in _run_module_as_main
mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
File "/usr/lib/python3.6/runpy.py", line 142, in _get_module_details
return _get_module_details(pkg_main_name, error)
File "/usr/lib/python3.6/runpy.py", line 109, in _get_module_details
__import__(pkg_name)
File "/usr/lib/python3.6/venv/__init__.py", line 10, in <module>
import subprocess
File "/usr/lib/python3.6/subprocess.py", line 136, in <module>
import _posixsubprocess
ModuleNotFoundError: No module named '_posixsubprocess'
Error in sys.excepthook:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
from apport.fileutils import likely_packaged, get_recent_crashes …