I would like to open a discussion around what might nightly build support in pypi look like.
First, a small IRC paste:

omry> What's the general take on publishing nightly releases to pypi? the package is not large (about 200kb now), but I am not sure if things like maintaining last X nightlies are doable (nuke old nightly as if they never existed).
mgedmin> my gut feeling is "please don't", but I'm not a pypa member
PSFSlack5> omry: If the project is small, it's not really a big deal.
omry> PSFSlack5: my concern is more about polluting the version name-space. is there a programmatic way to delete packages?
PSFSlack5> omry: There is not. Some projects do a separate project name entirely, like https://pypi.org/p/tf-nightly
omry> PSFSlack5, that's not a bad solution. It would be nice to have a programmatic interface to manipulate packages for cases like this.
omry> in the tf example, they upload about 1GB a day: https://pypi.org/project/tf-nightly/2.4.0.dev20201018/#files
omry> I don't think they want to keep old nightlies forever.
cooperlees> omry: Prob worth an issue / discussion @ https://github.com/pypa/warehouse/issues
cooperlees> I'd love to see nightlies be able to only keep the last x weeks of nightlies for example and stable releases. Would be helpful for bandersnatch / mirror peoples

Something that could be nice is a way to maintain X last nightly packages automatically and have older nightlies be automatically deleted.

The pip client can potentially provide a specific error for people who are trying to install deleted nightly packages, something like:

The nightly package foo==version expired. 
Please install a newer nightly package or switch to a stable release.
nightly versions: [newest K nightly versions]
stable versions: [newest K stable versions]

Pip should also not show nightly packages in the message it normally shows when there is a mismatch version number.