[RFC 0192] version pins for the pkgs/by-name structure

[quantenzitrone]

Rendered

Sorry if the RFC text is short, i don't know what else to write. The feature is quite simple.

[GetPsyched]

IMO versions should be a first-class feature of nixpkgs such that, to an end user, searching for a package should give you just one package with all of its versions listed as a part of it as opposed to each pinned version being its own exposed package (this argument could extend to package variants too but that goes out of scope).

This could go hand-in-hand with the current pins.nix approach too where the pins in it are not exposed at the top-level but simply as alternative versions to the existing package. As an end user, that's a far better UX than having multiple top-level packages for the same thing.

I know that this would involve significantly more work than the current proposal, but given that Nix's usability has been a concern for a long time, I'd want to push this along with this change since it might be harder down the line.

[7c6f434c]

The packages will still need to have default versions, doing otherwise is a usability disaster, and for pin.nix nothing changes if sbcl_2_0_0 is replaced with sbcl.versions."2.0.0"

So the change you propose is not reasonably tied to this one.

[vcunat]

There aren't just different .version numbers. You also have e.g. the *Full variants.

[7c6f434c]

I think this adds complexity to the version unification proposal but not to its interaction with the pins!

[GetPsyched]

I agree that this is not quite intersecting with the proposed change. I hoped to push this along since it's sort of related by increasing the scope of the RFC in case folks were interested. Sigh. Perhaps another day, in another RFC.

[quantenzitrone]

I changed the rfc text so it's more clear that it's about pinning dependency versions and not the packages themselves.
I also added pinning versions of the packages themselves under future work.

[robsliwi]

Related: NixOS/nixpkgs#421201