+++
date    = "2023-09-22T17:48:53+00:00"
lastmod = "2023-09-22T17:48:53+00:00"
tags    = [ "linux", "lists" ]
author  = "tdro"
+++

Some `nix` language gotchas I've experienced while using
[NixOS](https://nixos.org/explore) personally:

1. Avoid
   [`with`](https://nixos.org/manual/nix/stable/language/constructs#with-expressions)
   expressions unless with the
   [`inherit`](https://nixos.org/manual/nix/stable/language/constructs#inheriting-attributes)
   keyword for identifying hidden attributes in scope.
2. Avoid the
   [`rec`](https://nixos.org/manual/nix/stable/language/constructs#recursive-sets)
   keyword unless there's tracking/control of infinite set recursion (self
   naming/references).
3. Avoid importing more than 1 instance of
   [`<nixpkgs>`](https://github.com/NixOS/nixpkgs#readme) for any
   evaluation chain unless there's magic compute and "infinite" memory.

Tricky is numero three, but crucial for fast feedback regardless of the current
thing? I don't poke around as much to know anymore but;
[legacy](https://nixos.org/manual/nix/stable/command-ref/main-commands),
[flakes](https://nixos.org/manual/nix/stable/command-ref/experimental-commands),
[community](https://github.com/nix-community), and possibly others.