Clarify instructions for switching virtualenv (?)

Are the following instructions for using a new virtual environment still valid ?

> If you want to switch PyCall to use a different virtualenv, then you should switch virtualenvs and run rm(Pkg.dir("PyCall","deps","PYTHON")); Pkg.build("PyCall")

I'm unable to find any such file to delete in the given location.

Context: I am unable to get PyCall to use my virtual environment's version of Python (which was a pyenv install)

Thanks!