The older system without flakes can introduce impurities and unpredictable builds. While the newer system with flakes explicitly declares all dependencies, ensuring fully reproducible builds. Instead of nix search nixpkgs, people recommend using search.nixos.org to find packages.

Understanding the Context

Or if you really want to stay in the CLI you can use this command: Writing code with Nix-the-language is definitely on-topic here. Installation, probably not (as installing Nix is not a task unique to software development); you'd likely do better at discourse.nixos.org I'm trying to enable allow "unfree" packages, either globally or per-package, when using MyNixOS (excellent Flake configuration app for Nix) with Nix Flakes on Mac OS. When trying to inst... How to allow "unfree" packages in Nix, for each situation?: {NixOS, Nix ...

Key Insights

1 Overview I'm trying to setup tmux using nix and home-manager on macOS. However whenever I refresh the tmux config, I get the following errors: The NixOS cheatsheet describes how to install packages from unstable in configuration.nix. It starts off by saying to add the unstable channel like so: Add 'python39Full' to replit.nix if you want to install 'python3' in this repl. Unfortunately, I don't know how to add a package to .nix, so can anyone please tell me how to add a package to .nix? thanks.

Final Thoughts

(Replit) Nix: How do I add a package to .nix? - Stack Overflow