add more nixos post

content/posts/unstable-nixos.md

@@ -0,0 +1,39 @@
++++
+title = "Unstable software in NixOS"
+date = 2022-06-18
+draft = false
+
+[taxonomies]
+categories = [ "nixos" ]
+tags = [ "nixos", "nixos-22.05" ]
++++
+
+## Installing newer software
+
+Recently I ran into this [bug](https://github.com/NixOS/nixpkgs/issues/175512) with the stable (22.05 at this writing) of the ProtonVPN software in NixOS. A way to work around it was use the unstable version of the software which had the fix. I did a bit of Googling to find how to do that so I wanted to share what I found, this is the file that I use:
+
+    { config, pkgs, ...}:
+
+    let
+      unstable = import
+        (builtins.fetchTarball https://github.com/nixos/nixpkgs/tarball/master)
+        # reuse the current configuration
+        { config = config.nixpkgs.config; };
+    in
+    {
+      environment.systemPackages = with pkgs; [
+        unstable.protonvpn-cli
+        unstable.protonvpn-gui
+      ];
+    }
+
+Now I made this in a file like this `/etc/nixos/unstable-programs.nix` and then edit my `/etc/nixos/configuration.nix` file to import it like this:
+
+        [
+            ./hardware-configuration.nix
+            ./plasma.nix
+            ./programs.nix
+            ./unstable-programs.nix
+        ];
+
+That way I can comment it out once the fix is released or if I want to remove it for some reason. Once I made these edits to those two files I would rebuild and switch with this command `sudo nixos-rebuild switch` now if you want to test it just for the next reboot in case you are worried you can run this command instead `sudo nixos-rebuild test`. Now when you reboot it boots into that generation but if it doesn't work just reboot and you'll be in the previous generation without the change.