fix ci (#67)

* bump cachix action

* temporarily disable cachix

* remove deprecated overlay syntax

* update ci

.github/workflows/build.yml

@@ -1,36 +1,18 @@
-name: build
+name: "Test"
 on:
   pull_request:
   push:
 jobs:
-  build:
-    strategy:
-      matrix:
-        os:
-          - ubuntu-latest
-        nix:
-          - name: 2.5.1
-            url: https://releases.nixos.org/nix/nix-2.5.1/install
-    runs-on: ${{ matrix.os }}
+  tests:
+    runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2.3.5
-      - uses: cachix/install-nix-action@v15
-        with:
-          install_url: ${{ matrix.nix.url }}
-          extra_nix_config: |
-            experimental-features = nix-command flakes
-
-      - name: enable binary cache
-        uses: cachix/cachix-action@v10
-        with:
-          name: statix
-          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-
-      - run: nix flake check
-
-        # this also includes `cargo test`
-      - name: build statix
-        run: nix build -L
-
-      - name: build and install statix with flake-compat
-        run: nix-env -if default.nix
+    - uses: actions/checkout@v3
+    - uses: cachix/install-nix-action@v18
+      with:
+        github_access_token: ${{ secrets.GITHUB_TOKEN }}
+    - name: build statix
+      run: nix build -L
+    - name: test statix
+      run: nix flake check
+    - name: build statix and install statix in flake-compat mode
+      run: nix-env -if default.nix

flake.nix

@@ -29,7 +29,7 @@
       nixpkgsFor = forAllSystems (system:
         import nixpkgs {
           inherit system;
-          overlays = [ self.overlay ];
+          overlays = [ self.overlays.default ];
         });
 
       chanspec = {
@@ -42,7 +42,7 @@
     in
     {
 
-      overlay = final: prev: {
+      overlays.default = final: prev: {
 
         statix = with final;
           let