Merge pull request #312 from tricktron/fix-install-flake-github-action

Fixes install flake GitHub action

.github/workflows/test.yml

@@ -21,7 +21,6 @@ jobs:
     - run: |
         nix-channel --add https://nixos.org/channels/nixpkgs-20.09-darwin nixpkgs
         nix-channel --update
-        echo "FIXME workaround channel permission error"
     - run: |
         export NIX_PATH=$HOME/.nix-defexpr/channels
         nix-shell -A installer
@@ -38,17 +37,23 @@ jobs:
     timeout-minutes: 60
     steps:
     - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
     - uses: cachix/install-nix-action@v12
+      with:
+         install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20210207_fd6eaa1/install
+         extra_nix_config: |
+           experimental-features = nix-command flakes
+           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     - run: |
         nix-channel --add https://nixos.org/channels/nixpkgs-unstable nixpkgs
         nix-channel --update
     - run: |
-        NIX_PATH=$HOME/.nix-defexpr/channels nix-shell -A installer
-        echo "TODO installed doesn't support flakes, handle multi-user install"
+        export NIX_PATH=$HOME/.nix-defexpr/channels
+        nix-shell -A installer
     - run: |
-        nix-build channel:nixpkgs-unstable -A nixUnstable -o nix-unstable
-        ./nix-unstable/bin/nix --experimental-features 'nix-command flakes' registry add darwin $PWD
-        ./nix-unstable/bin/nix --experimental-features 'nix-command flakes' build ./modules/examples#darwinConfigurations.simple.system
+        nix registry add darwin $PWD
+        nix build ./modules/examples#darwinConfigurations.simple.system
     - run: |
         ./result/sw/bin/darwin-rebuild switch --flake ./modules/examples#simple
     - run: |

modules/examples/flake.nix

@@ -2,7 +2,7 @@
   description = "Example darwin system flake";
 
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-20.09-darwin";
+    nixpkgs.url = "github:nixos/nixpkgs";
     darwin.url = "github:lnl7/nix-darwin";
     darwin.inputs.nixpkgs.follows = "nixpkgs";
   };