Migrate: Update configuration to nixos-unstable channel

MIGRATION_TO_UNSTABLE.md

@@ -0,0 +1,176 @@
+# 🚀 Migration to nixos-unstable
+
+This guide walks you through migrating from NixOS 25.11 (stable) to nixos-unstable.
+
+## What is nixos-unstable?
+
+- **Stable (25.11)**: Tested, stable packages. Updated every ~6 months.
+- **Unstable**: Latest packages, updated continuously. May have occasional issues.
+
+## Why Migrate?
+
+✅ Latest software versions
+✅ Newest features and improvements  
+✅ Faster security updates
+⚠️ Slightly higher risk of breakage
+⚠️ Need to monitor updates more carefully
+
+## Migration Steps
+
+### Step 1: Update flake.nix ✅ (DONE)
+
+The flake.nix has been updated to use:
+- `nixpkgs/nixos-unstable` instead of `nixpkgs/nixos-25.11`
+- `home-manager/master` instead of `home-manager/release-25.11`
+
+### Step 2: Update the flake lock
+
+This downloads the new channel information:
+
+```bash
+cd ~/nixos-dotfiles
+nix flake update
+```
+
+This will update `flake.lock` to point to unstable versions.
+
+### Step 3: Test the new configuration
+
+Build without switching (safe test):
+
+```bash
+sudo nixos-rebuild build --flake ~/nixos-dotfiles/#nixos-btw
+```
+
+Or use the Makefile:
+
+```bash
+make build
+```
+
+If there are no errors, proceed to Step 4.
+
+### Step 4: Switch to unstable
+
+Apply the new configuration:
+
+```bash
+sudo nixos-rebuild switch --flake ~/nixos-dotfiles/#nixos-btw
+```
+
+Or:
+
+```bash
+make switch
+```
+
+### Step 5: Reboot
+
+```bash
+sudo reboot
+```
+
+### Step 6: Verify
+
+After reboot, check your NixOS version:
+
+```bash
+nixos-version
+```
+
+You should see something like `25.05.xxxxx` or higher (unstable doesn't have fixed versions).
+
+## Potential Issues & Solutions
+
+### Issue: Package not found
+
+Some package names change between stable and unstable.
+
+**Solution**: Check if the package was renamed:
+```bash
+nix search nixpkgs PACKAGE_NAME
+```
+
+### Issue: Build fails due to package conflicts
+
+**Solution**: 
+1. Check the error message carefully
+2. Comment out problematic packages temporarily
+3. Rebuild
+4. Search for alternatives or updated package names
+
+### Issue: Home Manager evaluation errors
+
+**Solution**: Home Manager on master branch may have API changes.
+Check the [Home Manager release notes](https://github.com/nix-community/home-manager/blob/master/CHANGELOG.md).
+
+### Issue: System doesn't boot
+
+**Solution**: Boot into previous generation from GRUB menu:
+1. Restart and enter GRUB menu
+2. Select "NixOS - All configurations"
+3. Choose previous working generation
+4. Boot into it
+5. Roll back: `sudo nixos-rebuild switch --rollback`
+
+## Rolling Back
+
+If you want to go back to stable:
+
+1. Edit `flake.nix` and change back to:
+   ```nix
+   nixpkgs.url = "nixpkgs/nixos-25.11";
+   home-manager.url = "github:nix-community/home-manager/release-25.11";
+   ```
+
+2. Update and switch:
+   ```bash
+   nix flake update
+   make switch
+   ```
+
+## Best Practices on Unstable
+
+1. **Update regularly** - Don't let updates pile up
+   ```bash
+   make update && make switch
+   ```
+
+2. **Monitor for breakage** - Check NixOS Discourse for known issues
+
+3. **Keep old generations** - Don't clean too aggressively
+   ```bash
+   # Keep last 30 days instead of 7
+   sudo nix-collect-garbage --delete-older-than 30d
+   ```
+
+4. **Test before switching** - Always use `make build` or `make test` first
+
+5. **Subscribe to updates** - Follow [@nixos_org](https://twitter.com/nixos_org) or [NixOS Discourse](https://discourse.nixos.org/)
+
+## Current Status
+
+- ✅ flake.nix updated to unstable
+- ⏳ Ready for `nix flake update`
+- ⏳ Ready to build and test
+- ⏳ Ready to switch
+
+## Quick Migration Commands
+
+```bash
+# Update to latest unstable
+nix flake update
+
+# Test the build
+make build
+
+# If successful, switch
+make switch
+
+# Reboot
+sudo reboot
+```
+
+---
+
+**Note**: The `system.stateVersion = "25.11"` in `core.nix` should NOT be changed. This tracks when you first installed NixOS, not which channel you're using.

flake.nix

@@ -3,12 +3,12 @@
 
   # Flake inputs - dependencies for this configuration
   inputs = {
-    # NixOS 25.11 stable channel
-    nixpkgs.url = "nixpkgs/nixos-25.11";
+    # NixOS unstable channel (bleeding edge)
+    nixpkgs.url = "nixpkgs/nixos-unstable";
     
     # Home Manager for user-level configuration management
     home-manager = {
-      url = "github:nix-community/home-manager/release-25.11";
+      url = "github:nix-community/home-manager/master";
       # Ensure Home Manager uses the same nixpkgs as system
       inputs.nixpkgs.follows = "nixpkgs";
     };

modules/nixos/core.nix

@@ -45,5 +45,6 @@
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
   # NixOS state version - DON'T change after initial installation
+  # This is the version you initially installed, not the channel you're using
   system.stateVersion = "25.11";
 }