add a nix flake to build just

[neunenak]

work in progress, I think it might be good to have a nix flake that builds the project for better integration into the nix ecosystem.

[casey]

Is this still something you're working on? I'm not sure I understand what a flake is for in this case, since Just is packaged in nixpkgs. And I thought a shell.nix, or something, was what you used for development. This is probably just ignorance on my part, since I am still confused by what a flake is 😅

[neunenak]

Is this still something you're working on? I'm not sure I understand what a flake is for in this case, since Just is packaged in nixpkgs. And I thought a shell.nix, or something, was what you used for development. This is probably just ignorance on my part, since I am still confused by what a flake is 😅

There are some benefits for people developing the project itself. Nix flakes are basically the modern, more-or-less-standard way to describe how to build and otherwise work with a software project in the nix ecosystem. In a flake.nix file you can define a devshell in the same way that shell.nix works, but also be more principled about pinning build inputs and do a few other things.

I think what I wanted this for was so that I could then define inputs in my own flake that look like `just.url = "github:casey/just", which would pin whatever git revision I wanted in a local lockfile and build exactly that version of just. Which lets someone using e.g. nix home-manager with flakes easily install the latest version without having to wait for a release or for the nixpkgs maintainers to update the official version. I got njbrake/agent-of-empires#309 merged into that project for basically the same reason.

Anyway I honestly forgot I had this draft PR open and now that I know claude can throw a basic build-rust flake.nix together pretty easily I'll probably ask it to fix whatever's broken about this PR and remove the draft.

[casey]

Sounds good, it seems useful.

[neunenak]

@casey this is ready for review now