direnv

Nixos and direnv have great interoperability. First enable direnv on nixos:

programs.direnv.enable = true;

Enable direnv in your shell: eval "$(direnv hook zsh)"

Then you can add .envrc files which contain: use nix and direnv will automatically run a shell.nix file in that directory:

{pkgs ? import <nixpkgs> {}}:
pkgs.mkShell {
  packages = [
    pkgs.gnumake
    pkgs.scdoc
    pkgs.go
    pkgs.golines
  ];
}

nixos-containers

NixOS allows you to easily run other NixOS instances as containers. Containers are a light-weight approach to virtualisation that runs software in the container at the same speed as in the host system.

find which package is providing a binary

This assumes you have the binary installed and need to determine which package is providing it:

ls -la $(which pkill)

nixos-flatpak

Useful for things you want to put in a slight sandbox so they don't litter files in your homedir (steam, slack, etc).