PEP 665, take 2 -- A file format to list Python dependencies for reproducibility of an application

[brettcannon]

@brettcannon

@pf_moore

This is another round of the “how intelligent must the installer be?” question. And to an extent, it’s 100% fair to say “it’s up to the installer”. But I think the PEP should state clearly what the minimum level of behaviour is that users can rely on. Even if that’s just the bare minumum “installers must do the right thing when installing a lockfile into an empty environment, but if there’s already packages other than the installer in the environment, behaviour is at the option of the installer”.

I think that’s fair. I will update the PEP.

Updated to say installer must support installing into an empty environment, but installing into an environment with packages already there is optional.