# Hybrid Package Management: Stable + Unstable

This NixOS configuration uses a hybrid approach where the system runs on the stable NixOS 24.05 branch but can selectively use packages from the unstable branch when needed.

## How It Works

The `flake.nix` includes both stable and unstable nixpkgs inputs:

```nix
inputs = {
  nixpkgs.url = "nixpkgs/nixos-24.05";           # Stable base
  nixpkgs-unstable.url = "nixpkgs/nixos-unstable"; # Unstable packages
  # ... other inputs
};
```

The unstable packages are made available to all system configurations via `specialArgs`:

```nix
nixosConfigurations = {
  framework = nixpkgs.lib.nixosSystem {
    system = "x86_64-linux";
    specialArgs = {
      pkgs-unstable = import nixpkgs-unstable {
        system = "x86_64-linux";
        config.allowUnfree = true;
      };
    };
    modules = [ /* ... */ ];
  };
};
```

## Using Unstable Packages

### In System Configuration Files

To use an unstable package in any `.nix` configuration file:

1. **Add `pkgs-unstable` to the function parameters:**
   ```nix
   { config, pkgs, pkgs-unstable, ... }:
   ```

2. **Use the unstable package:**
   ```nix
   environment.systemPackages = with pkgs; [
     # Stable packages
     firefox
     git
     
     # Unstable packages
     pkgs-unstable.windsurf
     pkgs-unstable.some-other-package
   ];
   ```

### Example: Current Usage

See `desktop/dev.nix` for a working example:

```nix
{ config, pkgs, pkgs-unstable, ... }:

{
  environment.systemPackages = with pkgs; [
    # Stable packages
    nodejs
    rpi-imager
    
    # Unstable packages
    pkgs-unstable.windsurf  # Use windsurf from unstable
  ];
}
```

## When to Use Unstable Packages

Use unstable packages when:
- A package is not available in the stable branch
- You need a newer version with specific features or bug fixes
- You're developing with cutting-edge tools

## Benefits of This Approach

1. **System Stability**: Core system components use stable, well-tested packages
2. **Package Availability**: Access to the latest packages when needed
3. **Selective Updates**: Choose which packages to get from unstable
4. **Easy Maintenance**: Clear separation between stable and unstable dependencies

## Adding New Unstable Packages

To add a new unstable package:

1. Find the configuration file where you want to add the package
2. Ensure the file accepts `pkgs-unstable` parameter
3. Add `pkgs-unstable.package-name` to the appropriate list
4. Test with `nixos-rebuild dry-run --flake .#framework`
5. Apply with `nixos-rebuild switch --flake .#framework`

## Updating Packages

- **Stable packages**: Updated when you update the flake lock
- **Unstable packages**: Updated when you run `nix flake update`

To update only unstable packages:
```bash
nix flake lock --update-input nixpkgs-unstable
```

## Current Unstable Packages in Use

- `windsurf` - Modern code editor (in `desktop/dev.nix`)

---

This hybrid approach gives you the stability of NixOS stable with the flexibility to use cutting-edge packages when needed.