I would love to see a discussion from somebody who really likes Nix on why it isn't ready for prime time yet/just play devil's advocate aloud on why it isn't the greatest thing since sliced bread.
I feel like I must not be doing anything "serious" enough to need package reproducibility at that high level. I'm aware of things like git checkout/tags, package-lock.json, Cargo.lock, Docker image tags.
What is a real world use case where Nix isn't overkill? I've read toolchains but... nvm (node version manager), rustup. I still Rust on a machine once and I never think about it again.
It feels like the Kubernetes of package management/build if you will complexity wise. "Do we really need this or is it just what everybody else is doing?"
Top reasons in my mind:
1. Error messages. Even with my >1 year of experience using NixOS full-time, I've encountered errors that I simply _cannot_ fix. This is getting better (recent nix releases let you introspect problems more easily).
2. Documentation gaps. Much of the nix docs are actually pretty good now! But sometimes you run into "missing links" that make it really hard.
> What is a real world use case where Nix isn't overkill? I've read toolchains but... nvm (node version manager), rustup. I still Rust on a machine once and I never think about it again.
For me, nix is unbelievably powerful to construct system images for various virtual machine formats. I'm using the nixos-generators[1] project to construct 8 or 9 image formats from one NixOS configuration. Packer and similar tools are the non-nix analog, but nixos-generators requires essentially adding a singular line to support something like Proxmox as opposed to much more work in some other tool.
I'm also using nix to build all our team's software - which varies from Vue.js to Rust to Django - and fold _all_ those development dependencies into a singular nix `devShell`. This means you can clone our repository, use `nix develop .`, and all engineers use the identical verisons of all software, dependencies, and libraries across several toolchains. It's incredibly convenient. (Imagine that you're a .js developer who needs to make a quick edit to a Rust backend route but doesn't sling Rust all day - you don't need to know how to setup rust at all, the `devShell` provides it).