Linux Administration Cookbook

Dependency problems in conflicting Pip packages

To better understand why virtualenv is a thing, we can look at an installation of Molecule.

In your Debian instance, install the Molecule testing framework (specifically, 2.15.0):

$ pip install molecule==2.15.0 --user

All being well, the installation should go fine, and you'll be able to check your Molecule version:

$ .local/bin/molecule --versionmolecule, version 2.15.0

However, we're now going to use install ansible-lint (the latest version, at the time of writing this book):

$ pip install ansible-lint==3.4.23 --user

Our installation works, but in the middle of it, we get a nasty warning:

molecule 2.15.0 has requirement ansible-lint==3.4.21, but you'll have ansible-lint 3.4.23 which is incompatible. ...