I try to provision my Vagrant boxes with the ansible_local provisioner. The other day I was using the pip ansible module while I was booting the box, but was getting errors while installing packages. It turns out that the pip version I had when I created the environment needed an upgrade. Sure you can run a pip install pip --upgrade from the command line, but how do you do so within a playbook? Pretty easy it seems:

---
- hosts: all
  tasks:
    - name: create the needed virtual environment and upgrade pip
      pip:
        chdir: /home/vagrant
        virtualenv: work
        virtualenv_command: /usr/bin/python3 -mvenv
        name: pip
        extra_args: --upgrade

    - name: now install the requirements
      pip:
        chdir: /home/vagrant
        virtualenv: work
        virtualenv_command: /usr/bin/python3 -mvenv
        requirements: /vagrant/requirements.txt

(Link to pastebin here in case the YAML above does not render correctly for you.)

I hope it helps you too.