Using multiple nixpkgs versions

[raspberric]

I tried to pin the nixpkgs version to 25.05 to try and fix an issue with trouble.nvim and so it can be the same version as in my other flakes. But then a plugin I was using was missing from 25.05 (prettier).
Is there a way I can tell nixCats utils to use normal pkgs + pkgsUnstable that I'd pass in? I'm still a noob to nix and couldn't figure it out on my own.

P.S. Amazing project 💯

[BirdeeHub]

Is there a way I can tell nixCats utils to use normal pkgs + pkgsUnstable that I'd pass in? I'm still a noob to nix and couldn't figure it out on my own.

So, in the location where you call the main builder function, nixCats.utils.baseBuilder, you pass it the pkgs it uses for everything.

You can also pass overlays to the builder function, when you do that they will be added to the pkgs or nixpkgs+system you pass in, and you can fetch the derivation you put in that overlay from any nixpkgs you want and supply it. You could instead apply them to the pkgs before you pass it in, doesnt matter.

You could use prev.stdenv.hostPlatforms.system or final.stdenv.hostPlatforms.system in an overlay, and put the package in there and grab it from the pkgs supplied to categoryDefinitions

OR, rather than messing around with overlays and being slightly confused as a new user:

Within categoryDefinitions you can use the pkgs.stdenv.hostPlatforms.system value to build a pkgs from an imported nixpkgs and fetch it there.

Unfortunately there is no way around having a "main" pkgs instance, but you can absolutely still fetch stuff from any version you want in several ways and even override values in the main one with things from other versions via overlays!

Or, you could download the plugin directly via flake input if its easy to build, that is also an option. Name it plugins-somename and pass inputs to standardPluginOverlay, OR just build it directly with mkPlugin which is supplied as argument to categoryDefintiions.

P.S. Amazing project 💯

Thanks!

I made a new project I am proud of (very) recently too!

https://github.com/BirdeeHub/nix-wrapper-modules

https://birdeehub.github.io/nix-wrapper-modules

[raspberric]

I appreciate the response! I ended up just adding it via flake input and pinning the version that way, since it's a single plugin that was causing an issue. But it's all valuable information to me in this stage.

nix-wrapper-modules looks very interesting too, seems like it will come in handy later in my nix journey.

[BirdeeHub]

nix-wrapper-modules looks very interesting too, seems like it will come in handy later in my nix journey.

I hope so! It should take off once people realize how many things they can't do in the project it is a rewrite of XD

It will take a little bit of time for that though, as people haven't done much exploring of the other one vs mine yet and the other one had a callout from vimjoyer before mine was written.

On the bright side, I have a bit of time to make sure the core helper modules are perfect before it has a bunch of users XD