Pipenv: --pre per–package

[gsemet]

This is a follow up on #1677.

pipenv lock doesn't work because I need a preversion of a single package. pipenv lock --pre does work but might add other, unwanted preversion in dependencies.

I would like to propose my help in implementing this feature: if one package needs to be frozen to a preversion (and only one), allow the dependency finding to pick this one even without the --pre parameter.

The --pre parameter which the preversion search for all packages, and sometimes we only want one package

[kennethreitz42]

This would be nice, but is not feasible (as far as I know) with the way our current resolver code works. It's either "all or nothing".

[techalchemy]

But if you know you want a specific package to be prerelease then you probably know what version, so (once we get the strict pinning bug sorted) you should be able to just pin the prerelease

[kennethreitz42]

+1, closing for that solution, for now. Our resolver just doesn't allow this yet.

[kennethreitz42]

Thanks for the suggestion, though!

[gsemet]

Hello @techalchemy If you reread my bug, this pinning of the release does not work if there are 2 packages describing the same dependency, where one says "a==1.0" and the other says "a>=1.0"; of course when the resolution is obvious but a human being (especially because the list after containst this very version)
When all packages says it wish "a==1.0", yes, pinning works.

[kennethreitz42]

please see #1687

[gsemet]

indeed, same issue

[tribals]

Well, I think, if the problem in resolver, there is need to replace it.

[tribals]

And not reject any issues just with "our resolver can't do that".