use more specific primary-key and prefix-match

.github/workflows/build-and-cache.yml

@@ -3,6 +3,61 @@ on:
   workflow_dispatch:
   push:
 jobs:
+  build-packages:
+    strategy:
+      matrix:
+        package:
+          - github:cything/nixpkgs/928e0c6874ab3e759305e93f806a4cf559645677#alvr
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - ubuntu-24.04-arm
+ 
+    runs-on: ${{ matrix.os }}
+    continue-on-error: true
+    steps:
+      - name: Install Nix
+        uses: cachix/install-nix-action@v30
+
+      - name: Sync repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - uses: cachix/cachix-action@v14
+        with:
+          name: cything
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          useDaemon: false
+          installCommand: nix profile install nixpkgs#cachix
+
+      - name: Setup Attic cache
+        uses: ryanccn/attic-action@v0
+        with:
+          endpoint: ${{ vars.ATTIC_ENDPOINT }}
+          cache: ${{ vars.ATTIC_CACHE }}
+          token: ${{ secrets.ATTIC_TOKEN }}
+
+      - name: Restore and cache Nix store
+        uses: nix-community/cache-nix-action@v5.1.0
+        with:
+          # restore and save a cache using this key
+          primary-key: nix-${{ runner.os }}-${{ matrix.machine }}-${{ hashFiles('**/*.nix', 'flake.lock') }}
+          # if there's no cache hit, restore a cache by this prefix
+          restore-prefixes-first-match: nix-${{ runner.os }}-${{ matrix.machine }}-
+          # do purge caches
+          purge: true
+          # purge all versions of the cache
+          purge-prefixes: nix-${{ runner.os }}-
+          # created more than this number of seconds ago relative to the start of the `Post Restore` phase
+          purge-last-accessed: 86400
+          # except the version with the `primary-key`, if it exists
+          purge-primary-key: never
+          # always save the cache
+          save-always: true
+
+      - run: nix build -L ${{ matrix.package }}
+
   build-machines:
     strategy:
       matrix:
@@ -53,9 +108,9 @@ jobs:
         uses: nix-community/cache-nix-action@v5.1.0
         with:
           # restore and save a cache using this key
-          primary-key: nix-${{ runner.os }}-${{ matrix.machine }}-${{ hashFiles('flake.lock') }}
+          primary-key: nix-${{ runner.os }}-${{ matrix.machine }}-${{ hashFiles('**/*.nix', 'flake.lock') }}
           # if there's no cache hit, restore a cache by this prefix
-          restore-prefixes-first-match: nix-${{ runner.os }}-
+          restore-prefixes-first-match: nix-${{ runner.os }}-${{ matrix.machine }}-
           # do purge caches
           purge: true
           # purge all versions of the cache
@@ -119,9 +174,9 @@ jobs:
         uses: nix-community/cache-nix-action@v5.1.0
         with:
           # restore and save a cache using this key
-          primary-key: nix-${{ runner.os }}-${{ matrix.home }}-${{ hashFiles('flake.lock') }}
+          primary-key: nix-${{ runner.os }}-${{ matrix.home }}-${{ hashFiles('**/*.nix', 'flake.lock') }}
           # if there's no cache hit, restore a cache by this prefix
-          restore-prefixes-first-match: nix-${{ runner.os }}-
+          restore-prefixes-first-match: nix-${{ runner.os }}-${{ matrix.home }}-
           # do purge caches
           purge: true
           # purge all versions of the cache