A new OS, another two hours wasted. Pop!_OS 19.10 comes with Python3.7rc5, which is nice but my project requires 3.6 just now. As you know we've gone through this before, but this time we can setup multiple python version support.

Let's setup pyenv, pip, pipenv and then install another python version.

# Setup pip.
curl https://bootstrap.pypa.io/get-pip.py | python

# Pip can setup pipenv.
pip install pipenv --user

# Manage multiple python versions through pyenv.
# @see https://github.com/pyenv/pyenv/wiki/Common-build-problems
sudo apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
xz-utils tk-dev libffi-dev liblzma-dev python-openssl git
curl https://pyenv.run | bash

Follow the instructions to add pyenv to the path. Now we can do stuff like:

# install another python version.
pyenv install 3.6.9

# OR let pipenv do it.
cd ~/dev/myproject
pipenv install --dev

Leave a comment if you have any issues, as this was written retrospectively.