From 1840ffb6140cf24a52598de226c7f88820ab4d79 Mon Sep 17 00:00:00 2001
From: Antoine Martin <antoine97.martin@gmail.com>
Date: Mon, 15 Feb 2021 17:23:25 +0100
Subject: [PATCH] flake: add nixpkgs-unstable overlay

---
 flake.lock | 19 ++++++++++++++++++-
 flake.nix  | 13 ++++++++++---
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/flake.lock b/flake.lock
index 2c438da..940b8a4 100644
--- a/flake.lock
+++ b/flake.lock
@@ -16,9 +16,26 @@
         "type": "github"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1613226215,
+        "narHash": "sha256-3rA5cGIrBHD6yeKhNhsF7/t461ww25oJY8KyBb0IhjU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "ff96a0fa5635770390b184ae74debea75c3fd534",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index aaf03ac..82ffe4c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,16 +2,23 @@
   description = "Nixos configuration with flakes";
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-20.09-small";
+    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = { self, nixpkgs }: {
-    nixosConfigurations.poseidon = nixpkgs.lib.nixosSystem {
+  outputs = { self, nixpkgs, nixpkgs-unstable }: {
+    nixosConfigurations.poseidon = nixpkgs.lib.nixosSystem rec {
       system = "x86_64-linux";
       modules =
         [
           ./poseidon.nix
+
           {
-            nixpkgs.overlays = import ./overlays;
+            nixpkgs.overlays = [
+              # packages accessible through pkgs.unstable.package
+              (final: prev: {
+                unstable = nixpkgs-unstable.legacyPackages.${system};
+              })
+            ] ++ (import ./overlays);
           }
         ];
     };