.travis.yml

# https://docs.travis-ci.com/user/languages/python/#using-tox-as-the-build-script
language: generic
before_install:
  # https://fabianlee.org/2018/02/11/ubuntu-a-centralized-apt-package-cache-using-apt-cacher-ng/
  - sudo apt-get install apt-cacher-ng
  - 'echo "PassThroughPattern: .*" | sudo tee -a /etc/apt-cacher-ng/acng.conf'
  - 'echo "VerboseLog: 2" | sudo tee -a /etc/apt-cacher-ng/acng.conf'
  - 'echo "Debug: 3" | sudo tee -a /etc/apt-cacher-ng/acng.conf'
  - 'sudo sed -i -e "/^CacheDir: .*/d" /etc/apt-cacher-ng/*.conf'
  - 'echo "CacheDir: ${HOME}/acng.cache" | sudo tee -a /etc/apt-cacher-ng/acng.conf'
  - 'sudo grep -r CacheDir /etc/apt-cacher-ng'
  - 'echo "Acquire::http::Proxy \"http://localhost:3142\";" | sudo tee /etc/apt/apt.conf.d/00proxy'
  - mkdir -p ~/acng.cache
  - chmod 755 ~
  - chmod 777 ~/acng.cache
  - chmod -R a+rwX ~/acng.cache
  - 'sudo ls -ld ~ ~/acng.cache'
  - 'sudo systemctl restart apt-cacher-ng || (sudo journalctl -xe; false;)'

  # https://websiteforstudents.com/how-to-install-python-3-8-on-ubuntu-18-04-16-04/
  - sudo apt update
  - sudo apt install software-properties-common
  - sudo add-apt-repository -y ppa:deadsnakes/ppa
  - sudo apt update
  # We need python3.8-distutils to avoid the error "ImportError: cannot import name 'dist'":
  # https://stackoverflow.com/a/62813917/648162
  - sudo apt -y install python3.6 python3.6-dev python3.7 python3.7-dev python3.8 python3.8-dev python3-pip python3.8-distutils
  - python3.7 -m pip install pipenv
  - # sudo cat /var/log/apt-cacher-ng/apt-cacher.*

script:
  # pipenv is having trouble finding the Python binary in its non-standard location on Travis:
  - python3.7 `which pipenv` --python `which python3.7` install --dev
  - python3.7 `which pipenv` run tox
  - # ls -la ~/.cache/pip ~/acng.cache

cache:
  directories:
  - $HOME/acng.cache
  # https://pip.pypa.io/en/stable/reference/pip_install/#caching
  - $HOME/.cache/pipenv