Manual caching

.gitea/workflows/build-pi-img.yml

@@ -13,6 +13,14 @@ jobs:
         uses: actions/checkout@v3.5.3
         with:
           ref: trunk
+
+      - name: "Cache Nix store"
+        uses: actions/cache@v3.0.8
+        id: nix-cache
+        with:
+          path: /tmp/nixcache
+          key: "pi-nix-cache-v1"
+
       - name: Install prerequisites
         run: apt update && apt install -y sudo zstd
       - name: Install Nix
@@ -23,8 +31,9 @@ jobs:
       - name: Remove access_tokens
         run: sed -i '/^access-tokens/d' /etc/nix/nix.conf
 
-      - name: Nix Magic Cache
-        uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
+      - name: "Import Nix store cache"
+        if: "steps.nix-cache.outputs.cache-hit == 'true'"
+        run: "nix-store --import < /tmp/nixcache"
 
       - name: Build image
         run: nix-build '<nixpkgs/nixos>' -A config.system.build.sdImage -I nixos-config=./pi-imgs/pi-initial.nix --argstr system aarch64-linux
@@ -34,3 +43,6 @@ jobs:
           name: nixos-pi-23.05-{{ env.GITHUB_SHA }}.img
           path: result/sd-image/*.img
 
+      - name: "Export Nix store cache"
+        if: "steps.nix-cache.outputs.cache-hit != 'true'"
+        run: "nix-store --export $(find /nix/store -maxdepth 1 -name '*-*') > /tmp/nixcache"