Have a look here: https://www.pantsbuild.org/docs/python-third-party-dependencies#multiple-lockfiles The keyword you're missing in your search is "resolve" and Pants supports multiple resolves. It sounds like you have 1 resolve per project plus 1 extra one for tests. You need to explicitly configure Pants to know about each resolve I think. I don't know much more about resolves than that, but folks who do should be along on Monday with more details if you're still stuck then.