在 Ubuntu 系统上使用 Python3.8 创建虚拟环境时报错：
$ python -m venv venv
The virtual environment was not created successfully because ensurepip is not
available. On Debian/Ubuntu systems, you need to install the python3-venv
package using the following command.
apt install python3.8-venv
You may need to use sudo with that command. After installing the python3-venv
package, recreate your virtual environment.
解决方案
报错信息中其实已经给了解决方案：
apt install python3.8-venv
当然，如果你不是 root 用户，得加上 sudo：
sudo apt install python3.8-venv
但还是报错：
$ sudo apt-get install python3.8-venv Reading package lists... Done Building dependency tree Reading state information... Done Package python3.8-venv is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'python3.8-venv' has no installation candidate
这个是因为 apt 好久没有更新了，更新一下：
sudo apt-get update
更新之后继续安装：
sudo apt install python3.8-venv
完美解决！
引用参考https://blog.csdn.net/lan120576664/article/details/50373571
