How to use python version or image name in cache key

Build Environment Caching Dependencies
3

Seeing the same issue (and the discussion board help actually found this topic to offer me!)

I can’t use a composite key that includes, say, {{ checksum ".venv/bin/python" }}, because the restore job doesn’t yet have that file to compute the checksum on.

This basic idea works for me:

commands:
  checkout-and-restore-deps:
    steps:
      - checkout
      - run: python --version > python_version
      - restore_cache:
          keys:
            - pipenv-v3-{{ .Branch }}-{{ checksum "Pipfile.lock" }}-{{ checksum "python_version" }}
            - pipenv-v3-{{ .Branch }}
            - pipenv-v3
jobs:
  restore-deps:
    executor: python
    environment: &common-env
      - PIPENV_VENV_IN_PROJECT: 1
      - PIPENV_NOSPIN: "TRUE"
    steps:
      - checkout-and-restore-deps
      - run:
          name: Wipe venv in case of stale symlink to old pyenv version
          command: |
            if [[ -d .venv/bin ]] && [[ ! -e .venv/bin/python ]]
              then pipenv --rm
            fi
      - run: pipenv sync --dev
      - save_cache:
          key: pipenv-v3-{{ .Branch }}-{{ checksum "Pipfile.lock" }}-{{ checksum "python_version" }}
          paths:
            - ".venv"