NixFlakesArch.md

🚀 Getting Started with Nix and Flakes on Arch Linux

This guide walks you through installing Nix, enabling flakes, and setting up a reproducible development environment on Arch Linux.

---

🔹 Step 1: Install Nix on Arch Linux

The recommended way to install Nix is via the official script:

sh <(curl -L https://nixos.org/nix/install) --daemon

After installation, reload your shell:

source /etc/profile

Verify the installation:

nix --version

---

🔹 Step 2: Enable Flakes

Since flakes are an experimental feature, they must be explicitly enabled.

Run the following command:

mkdir -p ~/.config/nix
echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf

Then restart your shell:

source /etc/profile

Check if flakes are enabled:

nix flake --help

If you see a help message, flakes are enabled! ✅

---

🔹 Step 3: Initialize a Flake Project

1️⃣ Create a new project directory and initialize Git:

mkdir nix-project && cd nix-project
git init

2️⃣ Create a flake.nix file:

nano flake.nix

Paste the following minimal flake setup:

{
  description = "A minimal Nix flake setup";

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

  outputs = { self, nixpkgs }:
  let
    system = "x86_64-linux";  # Define the architecture
    pkgs = nixpkgs.legacyPackages.${system};  # Correctly access package set
  in {
    devShells.${system}.default = pkgs.mkShell {
      nativeBuildInputs = with pkgs; [
        curl
        unzip
        gcc
        lcms2 
        wget
      ];

      shellHook = ''
        echo "Welcome to your Nix flake development shell!"
      '';
    };
  };
}

---

🔹 Step 4: Run Your Flake Development Shell

1️⃣ Ensure Git is clean (flakes require a Git repository):

git add .
git commit -m "Initial commit"

2️⃣ Update the flake:

nix flake update

3️⃣ Enter the flake development environment:

nix develop

---

🔹 Step 5: Exit the Nix Shell

To exit the Nix development shell, simply run:

exit

or press Ctrl + D.

---

🎉 Done!

You now have a fully reproducible Nix development environment using flakes! 🚀

If you need to update dependencies later, run:

nix flake update

To clean up unused packages:

nix-collect-garbage -d

---

✅ Summary of Commands

Task	Command
Install Nix	sh <(curl -L https://nixos.org/nix/install) --daemon
Enable flakes	echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf
Create a new project	mkdir nix-project && cd nix-project
Initialize Git	git init && git add . && git commit -m "Initial commit"
Run a flake shell	nix develop
Exit the shell	exit or Ctrl + D
Update flakes	nix flake update
Clean up unused dependencies	nix-collect-garbage -d