NixFlakes

Flakes

Introduction

• new systems to manage distro ecosystems including: nixos configuration, devellopement environment, dérivation, etc For comparaison:

  python --version
  python: cmd not found
   
  nix-shell -p python
   
  python --version
  Python 2.7.18.5

  or shell.nix

  with (import <nixpkgs> {});
  mkShell{
  	buildInputs = [
  		pkgs.vim
  		pkgs.neovim
  	];
  		
  	shellHook = ''
  		echo "Hello World"
  	'';
  }

  you need to use your channel witch is not good since you have to update So there might be not on the same version and will may be break your code

  • NixFlakes is easy solution

Installation

• Add the following to your system configuration (flakes):

    nix.settings.experimental-features = [ "nix-command" "flakes" ];

• Then initiate the flakes (do it in the directory you want to initiate)

  nix flake init

Configuration

• We can modify the flake.nix like this:

  { 
  	description = "my epic vims collection"; 
  	inputs = { 
  		nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable"; 
  	}; 
  	outputs = { self, nixpkgs }: 
  	let 
  		system = "x86_64-linux"; 
  		pkgs = nixpkgs.legacyPackages.${system}; 
  	in { 
  		bob = pkgs.mkShell { 
  			buildInputs = [ pkgs.neovim pkgs.vim ]; 
  			shellHook = '' echo "hello mom" ''; 
  		}; 
  	}; 
  }

Launch

nix develop

• To make the shell use BOB

  nix develop .#bob

• Update (new version of all dependencie)

  nix flakes update

Extra

CMD