feat: enable sccache for Darwin runners

Configure sccache on aarch64-darwin self-hosted runners with persistent cache disk mounting and Nix sandbox access via extra-sandbox-paths. Use jfroche/nix-eval-jobs fork with its own nixpkgs to maintain compatibility with existing warning fixes while avoiding lowdown build issues.

Author: yvan-sraka

.github/workflows/nix-build.yml

@@ -126,9 +126,26 @@ jobs:
       - name: Checkout Repo
         if: ${{ matrix.attr != '' }}
         uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - name: Mount sccache disk
+        if: ${{ matrix.attr != '' && matrix.postgresql_version }}
+        uses: useblacksmith/stickydisk@v1
+        with:
+          key: ${{ github.repository }}-sccache-${{ runner.os }}-${{ runner.arch }}-${{ matrix.cache_key }}
+          path: /nix/var/cache/sccache
       - name: Install nix
         if: ${{ matrix.attr != '' }}
         uses: ./.github/actions/nix-install-self-hosted
+      - name: Configure sccache for Nix builds
+        if: ${{ matrix.attr != '' && matrix.postgresql_version }}
+        run: |
+          # Ensure sccache directory exists
+          mkdir -p /nix/var/cache/sccache          
+          # Update Nix configuration to allow access to sccache directory in sandbox
+          if [ -w /etc/nix/nix.conf ]; then
+            tee -a /etc/nix/nix.conf > /dev/null <<EOF
+          extra-sandbox-paths = /nix/var/cache/sccache
+          EOF
+          fi
       - name: nix build
         if: ${{ matrix.attr != '' }}
         shell: bash
@@ -149,9 +166,26 @@ jobs:
       - name: Checkout Repo
         if: ${{ matrix.attr != '' }}
         uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - name: Mount sccache disk
+        if: ${{ matrix.attr != '' && matrix.postgresql_version }}
+        uses: useblacksmith/stickydisk@v1
+        with:
+          key: ${{ github.repository }}-sccache-${{ runner.os }}-${{ runner.arch }}-${{ matrix.cache_key }}
+          path: /nix/var/cache/sccache
       - name: Install nix
         if: ${{ matrix.attr != '' }}
         uses: ./.github/actions/nix-install-self-hosted
+      - name: Configure sccache for Nix builds
+        if: ${{ matrix.attr != '' && matrix.postgresql_version }}
+        run: |
+          # Ensure sccache directory exists
+          mkdir -p /nix/var/cache/sccache          
+          # Update Nix configuration to allow access to sccache directory in sandbox
+          if [ -w /etc/nix/nix.conf ]; then
+            tee -a /etc/nix/nix.conf > /dev/null <<EOF
+          extra-sandbox-paths = /nix/var/cache/sccache
+          EOF
+          fi
       - name: nix build
         if: ${{ matrix.attr != '' }}
         shell: bash

flake.lock

@@ -20,7 +20,7 @@
     nix-editor.url = "github:snowfallorg/nix-editor";
     nix-eval-jobs.inputs.flake-parts.follows = "flake-parts";
     nix-eval-jobs.inputs.treefmt-nix.follows = "treefmt-nix";
-    nix-eval-jobs.url = "github:nix-community/nix-eval-jobs";
+    nix-eval-jobs.url = "github:jfroche/nix-eval-jobs/fix-warnings";
     nix2container.inputs.nixpkgs.follows = "nixpkgs";
     nix2container.url = "github:nlewo/nix2container";
     # Pin to a specific nixpkgs version that has compatible v8 and curl versions