Quick-to-build c++ dev environment on darwin

[waffle8946]

Clang, clang++, and clangd can't find headers, even with compile_commands.json

What you’re meant to do is override the stdenv if you want it to use clang: pkgs.mkShell.override { stdenv = clang19Stdenv; } { packages = [ pkgs.cmake # ... whatever else, but NOT C compilers though! ]; } (or inherit (llvmPackages_19) stdenv;, if you prefer) and instead of the deprecated devShell.<system>, use devShells.<system>.default.

Also, I think on darwin clang is the default anyway… just remove clang entirely.

@mackeye

nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

Replace nixos-unstable with nixpkgs-unstable on darwin.