[xapata]

> Running a pip freeze to generate a requirements.txt file doesn't work nicely when you use a requirements.txt file to define your top level dependencies.

Use setup.cfg to define your top level dependencies. Use requirements.txt as your "lock" file. But even then you won't get reproducible builds across different OSes, or with different non-Python things installed on your machines. Use Docker images to guarantee staging and production will be identical.