From b029ebe4251bb5b6136409d30780508f286471db Mon Sep 17 00:00:00 2001
From: Kamil Monicz <kamil@monicz.dev>
Date: Mon, 19 Feb 2024 14:37:31 +0100
Subject: [PATCH] Cache nix store by nixpkgs hash as a key

---
 .github/workflows/deploy.yaml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/deploy.yaml b/.github/workflows/deploy.yaml
index 8fdef70..2e914e8 100644
--- a/.github/workflows/deploy.yaml
+++ b/.github/workflows/deploy.yaml
@@ -26,11 +26,16 @@ jobs:
         with:
           nix_path: nixpkgs=channel:nixpkgs-23.11-darwin
 
+      - name: Extract nixpkgs hash
+        run: |
+          nixpkgs_hash=$(grep -o -P '(?<=archive/)[0-9a-f]{40}(?=\.tar\.gz)' shell.nix)
+          echo "NIXPKGS_HASH=$nixpkgs_hash" >> $GITHUB_ENV
+
       - name: Cache Nix store
         uses: actions/cache@v4
         id: nix-cache
         with:
-          key: nix-${{ runner.os }}-${{ hashFiles('shell.nix') }}
+          key: nix-${{ runner.os }}-${{ env.NIXPKGS_HASH }}
           path: /tmp/nix-cache
 
       - name: Import Nix store cache