Copy an existing pyenv virtualenv into a new one
git clone https://github.com/engigu/pyenv-virtualenv-copy.git $(pyenv root)/plugins/pyenv-virtualenv-copy
for China, you can use this.
git clone https://hub.fastgit.xyz/engigu/pyenv-virtualenv-copy.git $(pyenv root)/plugins/pyenv-virtualenv-copy
pyenv virtualenv-copy <existed-name> <new-name>
rm $(pyenv root)/plugins/pyenv-virtualenv-copy -rf